cmd/compile: represent derived types with ir.DynamicType in unified IR

This CL switches unified IR to using ir.DynamicType for derived
types. This has an immediate effect of fixing compilation of generic
code that when fully stenciled results in statically invalid type
assertions. This does require updating typecheck to expect
ODYNAMICTYPE in type switches, but this is straightforward to
implement.

For now, we still statically resolve the runtime type (or itab)
pointer. However, a subsequent CL will allow reading these pointers
from the runtime dictionary.

Change-Id: I1666678fcc588bc9cb8b97871bd02b9059848e6d
Reviewed-on: https://go-review.googlesource.com/c/go/+/390336
Trust: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>

2 files changed, 32 insertions, 30 deletions

diff --git a/src/internal/pkgbits/sync.go b/src/internal/pkgbits/sync.go
index b2c9139ce6..6eae306b22 100644
--- a/src/internal/pkgbits/sync.go
+++ b/src/internal/pkgbits/sync.go
@@ -92,6 +92,7 @@ const (
 	SyncExprList
 	SyncExprs
 	SyncExpr
+	SyncExprType
 	SyncOp
 	SyncFuncLit
 	SyncCompLit
diff --git a/src/internal/pkgbits/syncmarker_string.go b/src/internal/pkgbits/syncmarker_string.go
index 91154a001d..39db9eddad 100644
--- a/src/internal/pkgbits/syncmarker_string.go
+++ b/src/internal/pkgbits/syncmarker_string.go
@@ -44,39 +44,40 @@ func _() {
 	_ = x[SyncExprList-34]
 	_ = x[SyncExprs-35]
 	_ = x[SyncExpr-36]
-	_ = x[SyncOp-37]
-	_ = x[SyncFuncLit-38]
-	_ = x[SyncCompLit-39]
-	_ = x[SyncDecl-40]
-	_ = x[SyncFuncBody-41]
-	_ = x[SyncOpenScope-42]
-	_ = x[SyncCloseScope-43]
-	_ = x[SyncCloseAnotherScope-44]
-	_ = x[SyncDeclNames-45]
-	_ = x[SyncDeclName-46]
-	_ = x[SyncStmts-47]
-	_ = x[SyncBlockStmt-48]
-	_ = x[SyncIfStmt-49]
-	_ = x[SyncForStmt-50]
-	_ = x[SyncSwitchStmt-51]
-	_ = x[SyncRangeStmt-52]
-	_ = x[SyncCaseClause-53]
-	_ = x[SyncCommClause-54]
-	_ = x[SyncSelectStmt-55]
-	_ = x[SyncDecls-56]
-	_ = x[SyncLabeledStmt-57]
-	_ = x[SyncUseObjLocal-58]
-	_ = x[SyncAddLocal-59]
-	_ = x[SyncLinkname-60]
-	_ = x[SyncStmt1-61]
-	_ = x[SyncStmtsEnd-62]
-	_ = x[SyncLabel-63]
-	_ = x[SyncOptLabel-64]
+	_ = x[SyncExprType-37]
+	_ = x[SyncOp-38]
+	_ = x[SyncFuncLit-39]
+	_ = x[SyncCompLit-40]
+	_ = x[SyncDecl-41]
+	_ = x[SyncFuncBody-42]
+	_ = x[SyncOpenScope-43]
+	_ = x[SyncCloseScope-44]
+	_ = x[SyncCloseAnotherScope-45]
+	_ = x[SyncDeclNames-46]
+	_ = x[SyncDeclName-47]
+	_ = x[SyncStmts-48]
+	_ = x[SyncBlockStmt-49]
+	_ = x[SyncIfStmt-50]
+	_ = x[SyncForStmt-51]
+	_ = x[SyncSwitchStmt-52]
+	_ = x[SyncRangeStmt-53]
+	_ = x[SyncCaseClause-54]
+	_ = x[SyncCommClause-55]
+	_ = x[SyncSelectStmt-56]
+	_ = x[SyncDecls-57]
+	_ = x[SyncLabeledStmt-58]
+	_ = x[SyncUseObjLocal-59]
+	_ = x[SyncAddLocal-60]
+	_ = x[SyncLinkname-61]
+	_ = x[SyncStmt1-62]
+	_ = x[SyncStmtsEnd-63]
+	_ = x[SyncLabel-64]
+	_ = x[SyncOptLabel-65]
 }
 
-const _SyncMarker_name = "EOFBoolInt64Uint64StringValueValRelocsRelocUseRelocPublicPosPosBaseObjectObject1PkgPkgDefMethodTypeTypeIdxTypeParamNamesSignatureParamsParamCodeObjSymLocalIdentSelectorPrivateFuncExtVarExtTypeExtPragmaExprListExprsExprOpFuncLitCompLitDeclFuncBodyOpenScopeCloseScopeCloseAnotherScopeDeclNamesDeclNameStmtsBlockStmtIfStmtForStmtSwitchStmtRangeStmtCaseClauseCommClauseSelectStmtDeclsLabeledStmtUseObjLocalAddLocalLinknameStmt1StmtsEndLabelOptLabel"
+const _SyncMarker_name = "EOFBoolInt64Uint64StringValueValRelocsRelocUseRelocPublicPosPosBaseObjectObject1PkgPkgDefMethodTypeTypeIdxTypeParamNamesSignatureParamsParamCodeObjSymLocalIdentSelectorPrivateFuncExtVarExtTypeExtPragmaExprListExprsExprAssertTypeOpFuncLitCompLitDeclFuncBodyOpenScopeCloseScopeCloseAnotherScopeDeclNamesDeclNameStmtsBlockStmtIfStmtForStmtSwitchStmtRangeStmtCaseClauseCommClauseSelectStmtDeclsLabeledStmtUseObjLocalAddLocalLinknameStmt1StmtsEndLabelOptLabel"
 
-var _SyncMarker_index = [...]uint16{0, 3, 7, 12, 18, 24, 29, 32, 38, 43, 51, 57, 60, 67, 73, 80, 83, 89, 95, 99, 106, 120, 129, 135, 140, 147, 150, 160, 168, 175, 182, 188, 195, 201, 209, 214, 218, 220, 227, 234, 238, 246, 255, 265, 282, 291, 299, 304, 313, 319, 326, 336, 345, 355, 365, 375, 380, 391, 402, 410, 418, 423, 431, 436, 444}
+var _SyncMarker_index = [...]uint16{0, 3, 7, 12, 18, 24, 29, 32, 38, 43, 51, 57, 60, 67, 73, 80, 83, 89, 95, 99, 106, 120, 129, 135, 140, 147, 150, 160, 168, 175, 182, 188, 195, 201, 209, 214, 218, 228, 230, 237, 244, 248, 256, 265, 275, 292, 301, 309, 314, 323, 329, 336, 346, 355, 365, 375, 385, 390, 401, 412, 420, 428, 433, 441, 446, 454}
 
 func (i SyncMarker) String() string {
 	i -= 1