cmd/link,cmd/internal: add R_GOT_PCREL_ITYPE_RELOC for riscv64

This CL adds new relocation type for riscv64: R_GOT_PCREL_ITYPE_RELOC
which generate an AUIPC + I-type pair with relocation type of GOT_HI20
and PCREL_LO12_I.
According to RISCV elf psabi doc, medium position independent code
model, the GNU as example is:

```
		# Calculate address of non-local symbol
.Ltmp3: aupipc	a0, %got_pcrel_hi(symbol)
	ld	a0, %pcrel_lo(.Ltmp3)(a0)
```

Change-Id: I719dd05e009ca2d9291f0689b346c059f9c56918
Reviewed-on: https://go-review.googlesource.com/c/go/+/612635
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Reviewed-by: Joel Sing <joel@sing.id.au>
Reviewed-by: Cherry Mui <cherryyz@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

2 files changed, 35 insertions, 30 deletions

diff --git a/src/cmd/internal/objabi/reloctype.go b/src/cmd/internal/objabi/reloctype.go
index 9106b085ea..8e9bee5082 100644
--- a/src/cmd/internal/objabi/reloctype.go
+++ b/src/cmd/internal/objabi/reloctype.go
@@ -291,6 +291,10 @@ const (
 	// address.
 	R_RISCV_GOT_HI20
 
+	// R_RISCV_GOT_PCREL_ITYPE resolves a 32-bit PC-relative GOT entry
+	// address for an AUIPC + I-type instruction pair.
+	R_RISCV_GOT_PCREL_ITYPE
+
 	// R_RISCV_PCREL_HI20 resolves the high 20 bits of a 32-bit PC-relative
 	// address.
 	R_RISCV_PCREL_HI20
diff --git a/src/cmd/internal/objabi/reloctype_string.go b/src/cmd/internal/objabi/reloctype_string.go
index fd0e401db1..2d8a9554eb 100644
--- a/src/cmd/internal/objabi/reloctype_string.go
+++ b/src/cmd/internal/objabi/reloctype_string.go
@@ -75,39 +75,40 @@ func _() {
 	_ = x[R_RISCV_TLS_IE-65]
 	_ = x[R_RISCV_TLS_LE-66]
 	_ = x[R_RISCV_GOT_HI20-67]
-	_ = x[R_RISCV_PCREL_HI20-68]
-	_ = x[R_RISCV_PCREL_LO12_I-69]
-	_ = x[R_RISCV_PCREL_LO12_S-70]
-	_ = x[R_RISCV_BRANCH-71]
-	_ = x[R_RISCV_RVC_BRANCH-72]
-	_ = x[R_RISCV_RVC_JUMP-73]
-	_ = x[R_PCRELDBL-74]
-	_ = x[R_LOONG64_ADDR_HI-75]
-	_ = x[R_LOONG64_ADDR_LO-76]
-	_ = x[R_LOONG64_TLS_LE_HI-77]
-	_ = x[R_LOONG64_TLS_LE_LO-78]
-	_ = x[R_CALLLOONG64-79]
-	_ = x[R_LOONG64_TLS_IE_HI-80]
-	_ = x[R_LOONG64_TLS_IE_LO-81]
-	_ = x[R_LOONG64_GOT_HI-82]
-	_ = x[R_LOONG64_GOT_LO-83]
-	_ = x[R_LOONG64_ADD64-84]
-	_ = x[R_LOONG64_SUB64-85]
-	_ = x[R_JMP16LOONG64-86]
-	_ = x[R_JMP21LOONG64-87]
-	_ = x[R_JMPLOONG64-88]
-	_ = x[R_ADDRMIPSU-89]
-	_ = x[R_ADDRMIPSTLS-90]
-	_ = x[R_ADDRCUOFF-91]
-	_ = x[R_WASMIMPORT-92]
-	_ = x[R_XCOFFREF-93]
-	_ = x[R_PEIMAGEOFF-94]
-	_ = x[R_INITORDER-95]
+	_ = x[R_RISCV_GOT_PCREL_ITYPE-68]
+	_ = x[R_RISCV_PCREL_HI20-69]
+	_ = x[R_RISCV_PCREL_LO12_I-70]
+	_ = x[R_RISCV_PCREL_LO12_S-71]
+	_ = x[R_RISCV_BRANCH-72]
+	_ = x[R_RISCV_RVC_BRANCH-73]
+	_ = x[R_RISCV_RVC_JUMP-74]
+	_ = x[R_PCRELDBL-75]
+	_ = x[R_LOONG64_ADDR_HI-76]
+	_ = x[R_LOONG64_ADDR_LO-77]
+	_ = x[R_LOONG64_TLS_LE_HI-78]
+	_ = x[R_LOONG64_TLS_LE_LO-79]
+	_ = x[R_CALLLOONG64-80]
+	_ = x[R_LOONG64_TLS_IE_HI-81]
+	_ = x[R_LOONG64_TLS_IE_LO-82]
+	_ = x[R_LOONG64_GOT_HI-83]
+	_ = x[R_LOONG64_GOT_LO-84]
+	_ = x[R_LOONG64_ADD64-85]
+	_ = x[R_LOONG64_SUB64-86]
+	_ = x[R_JMP16LOONG64-87]
+	_ = x[R_JMP21LOONG64-88]
+	_ = x[R_JMPLOONG64-89]
+	_ = x[R_ADDRMIPSU-90]
+	_ = x[R_ADDRMIPSTLS-91]
+	_ = x[R_ADDRCUOFF-92]
+	_ = x[R_WASMIMPORT-93]
+	_ = x[R_XCOFFREF-94]
+	_ = x[R_PEIMAGEOFF-95]
+	_ = x[R_INITORDER-96]
 }
 
-const _RelocType_name = "R_ADDRR_ADDRPOWERR_ADDRARM64R_ADDRMIPSR_ADDROFFR_SIZER_CALLR_CALLARMR_CALLARM64R_CALLINDR_CALLPOWERR_CALLMIPSR_CONSTR_PCRELR_TLS_LER_TLS_IER_GOTOFFR_PLT0R_PLT1R_PLT2R_USEFIELDR_USETYPER_USEIFACER_USEIFACEMETHODR_USENAMEDMETHODR_METHODOFFR_KEEPR_POWER_TOCR_GOTPCRELR_JMPMIPSR_DWARFSECREFR_DWARFFILEREFR_ARM64_TLS_LER_ARM64_TLS_IER_ARM64_GOTPCRELR_ARM64_GOTR_ARM64_PCRELR_ARM64_PCREL_LDST8R_ARM64_PCREL_LDST16R_ARM64_PCREL_LDST32R_ARM64_PCREL_LDST64R_ARM64_LDST8R_ARM64_LDST16R_ARM64_LDST32R_ARM64_LDST64R_ARM64_LDST128R_POWER_TLS_LER_POWER_TLS_IER_POWER_TLSR_POWER_TLS_IE_PCREL34R_POWER_TLS_LE_TPREL34R_ADDRPOWER_DSR_ADDRPOWER_GOTR_ADDRPOWER_GOT_PCREL34R_ADDRPOWER_PCRELR_ADDRPOWER_TOCRELR_ADDRPOWER_TOCREL_DSR_ADDRPOWER_D34R_ADDRPOWER_PCREL34R_RISCV_JALR_RISCV_JAL_TRAMPR_RISCV_CALLR_RISCV_PCREL_ITYPER_RISCV_PCREL_STYPER_RISCV_TLS_IER_RISCV_TLS_LER_RISCV_GOT_HI20R_RISCV_PCREL_HI20R_RISCV_PCREL_LO12_IR_RISCV_PCREL_LO12_SR_RISCV_BRANCHR_RISCV_RVC_BRANCHR_RISCV_RVC_JUMPR_PCRELDBLR_LOONG64_ADDR_HIR_LOONG64_ADDR_LOR_LOONG64_TLS_LE_HIR_LOONG64_TLS_LE_LOR_CALLLOONG64R_LOONG64_TLS_IE_HIR_LOONG64_TLS_IE_LOR_LOONG64_GOT_HIR_LOONG64_GOT_LOR_LOONG64_ADD64R_LOONG64_SUB64R_JMP16LOONG64R_JMP21LOONG64R_JMPLOONG64R_ADDRMIPSUR_ADDRMIPSTLSR_ADDRCUOFFR_WASMIMPORTR_XCOFFREFR_PEIMAGEOFFR_INITORDER"
+const _RelocType_name = "R_ADDRR_ADDRPOWERR_ADDRARM64R_ADDRMIPSR_ADDROFFR_SIZER_CALLR_CALLARMR_CALLARM64R_CALLINDR_CALLPOWERR_CALLMIPSR_CONSTR_PCRELR_TLS_LER_TLS_IER_GOTOFFR_PLT0R_PLT1R_PLT2R_USEFIELDR_USETYPER_USEIFACER_USEIFACEMETHODR_USENAMEDMETHODR_METHODOFFR_KEEPR_POWER_TOCR_GOTPCRELR_JMPMIPSR_DWARFSECREFR_DWARFFILEREFR_ARM64_TLS_LER_ARM64_TLS_IER_ARM64_GOTPCRELR_ARM64_GOTR_ARM64_PCRELR_ARM64_PCREL_LDST8R_ARM64_PCREL_LDST16R_ARM64_PCREL_LDST32R_ARM64_PCREL_LDST64R_ARM64_LDST8R_ARM64_LDST16R_ARM64_LDST32R_ARM64_LDST64R_ARM64_LDST128R_POWER_TLS_LER_POWER_TLS_IER_POWER_TLSR_POWER_TLS_IE_PCREL34R_POWER_TLS_LE_TPREL34R_ADDRPOWER_DSR_ADDRPOWER_GOTR_ADDRPOWER_GOT_PCREL34R_ADDRPOWER_PCRELR_ADDRPOWER_TOCRELR_ADDRPOWER_TOCREL_DSR_ADDRPOWER_D34R_ADDRPOWER_PCREL34R_RISCV_JALR_RISCV_JAL_TRAMPR_RISCV_CALLR_RISCV_PCREL_ITYPER_RISCV_PCREL_STYPER_RISCV_TLS_IER_RISCV_TLS_LER_RISCV_GOT_HI20R_RISCV_GOT_PCREL_ITYPER_RISCV_PCREL_HI20R_RISCV_PCREL_LO12_IR_RISCV_PCREL_LO12_SR_RISCV_BRANCHR_RISCV_RVC_BRANCHR_RISCV_RVC_JUMPR_PCRELDBLR_LOONG64_ADDR_HIR_LOONG64_ADDR_LOR_LOONG64_TLS_LE_HIR_LOONG64_TLS_LE_LOR_CALLLOONG64R_LOONG64_TLS_IE_HIR_LOONG64_TLS_IE_LOR_LOONG64_GOT_HIR_LOONG64_GOT_LOR_LOONG64_ADD64R_LOONG64_SUB64R_JMP16LOONG64R_JMP21LOONG64R_JMPLOONG64R_ADDRMIPSUR_ADDRMIPSTLSR_ADDRCUOFFR_WASMIMPORTR_XCOFFREFR_PEIMAGEOFFR_INITORDER"
 
-var _RelocType_index = [...]uint16{0, 6, 17, 28, 38, 47, 53, 59, 68, 79, 88, 99, 109, 116, 123, 131, 139, 147, 153, 159, 165, 175, 184, 194, 210, 226, 237, 243, 254, 264, 273, 286, 300, 314, 328, 344, 355, 368, 387, 407, 427, 447, 460, 474, 488, 502, 517, 531, 545, 556, 578, 600, 614, 629, 652, 669, 687, 708, 723, 742, 753, 770, 782, 801, 820, 834, 848, 864, 882, 902, 922, 936, 954, 970, 980, 997, 1014, 1033, 1052, 1065, 1084, 1103, 1119, 1135, 1150, 1165, 1179, 1193, 1205, 1216, 1229, 1240, 1252, 1262, 1274, 1285}
+var _RelocType_index = [...]uint16{0, 6, 17, 28, 38, 47, 53, 59, 68, 79, 88, 99, 109, 116, 123, 131, 139, 147, 153, 159, 165, 175, 184, 194, 210, 226, 237, 243, 254, 264, 273, 286, 300, 314, 328, 344, 355, 368, 387, 407, 427, 447, 460, 474, 488, 502, 517, 531, 545, 556, 578, 600, 614, 629, 652, 669, 687, 708, 723, 742, 753, 770, 782, 801, 820, 834, 848, 864, 887, 905, 925, 945, 959, 977, 993, 1003, 1020, 1037, 1056, 1075, 1088, 1107, 1126, 1142, 1158, 1173, 1188, 1202, 1216, 1228, 1239, 1252, 1263, 1275, 1285, 1297, 1308}
 
 func (i RelocType) String() string {
 	i -= 1