internal/buildcfg: move build configuration out of cmd/internal/objabi

The go/build package needs access to this configuration,
so move it into a new package available to the standard library.

Change-Id: I868a94148b52350c76116451f4ad9191246adcff
Reviewed-on: https://go-review.googlesource.com/c/go/+/310731
Trust: Russ Cox <rsc@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Jay Conrod <jayconrod@google.com>

2 files changed, 6 insertions, 4 deletions

diff --git a/src/cmd/internal/obj/arm/asm5.go b/src/cmd/internal/obj/arm/asm5.go
index ebb98b4859..ccf5f9e7f8 100644
--- a/src/cmd/internal/obj/arm/asm5.go
+++ b/src/cmd/internal/obj/arm/asm5.go
@@ -34,6 +34,7 @@ import (
 	"cmd/internal/obj"
 	"cmd/internal/objabi"
 	"fmt"
+	"internal/buildcfg"
 	"log"
 	"math"
 	"sort"
@@ -976,7 +977,7 @@ func (c *ctxt5) aclass(a *obj.Addr) int {
 			if immrot(^uint32(c.instoffset)) != 0 {
 				return C_NCON
 			}
-			if uint32(c.instoffset) <= 0xffff && objabi.GOARM == 7 {
+			if uint32(c.instoffset) <= 0xffff && buildcfg.GOARM == 7 {
 				return C_SCON
 			}
 			if x, y := immrot2a(uint32(c.instoffset)); x != 0 && y != 0 {
@@ -3044,7 +3045,7 @@ func (c *ctxt5) omvl(p *obj.Prog, a *obj.Addr, dr int) uint32 {
 
 func (c *ctxt5) chipzero5(e float64) int {
 	// We use GOARM=7 to gate the use of VFPv3 vmov (imm) instructions.
-	if objabi.GOARM < 7 || math.Float64bits(e) != 0 {
+	if buildcfg.GOARM < 7 || math.Float64bits(e) != 0 {
 		return -1
 	}
 	return 0
@@ -3052,7 +3053,7 @@ func (c *ctxt5) chipzero5(e float64) int {
 
 func (c *ctxt5) chipfloat5(e float64) int {
 	// We use GOARM=7 to gate the use of VFPv3 vmov (imm) instructions.
-	if objabi.GOARM < 7 {
+	if buildcfg.GOARM < 7 {
 		return -1
 	}
 
diff --git a/src/cmd/internal/obj/arm/obj5.go b/src/cmd/internal/obj/arm/obj5.go
index edb384806b..1454d8a7c9 100644
--- a/src/cmd/internal/obj/arm/obj5.go
+++ b/src/cmd/internal/obj/arm/obj5.go
@@ -34,6 +34,7 @@ import (
 	"cmd/internal/obj"
 	"cmd/internal/objabi"
 	"cmd/internal/sys"
+	"internal/buildcfg"
 	"log"
 )
 
@@ -64,7 +65,7 @@ func progedit(ctxt *obj.Link, p *obj.Prog, newprog obj.ProgAlloc) {
 				ctxt.Diag("%v: TLS MRC instruction must write to R0 as it might get translated into a BL instruction", p.Line())
 			}
 
-			if objabi.GOARM < 7 {
+			if buildcfg.GOARM < 7 {
 				// Replace it with BL runtime.read_tls_fallback(SB) for ARM CPUs that lack the tls extension.
 				if progedit_tlsfallback == nil {
 					progedit_tlsfallback = ctxt.Lookup("runtime.read_tls_fallback")