[dev.link] all: merge branch 'master' into dev.link

Bring in Than's fix of #35779.

The only merge conflict is cmd/link/internal/loadelf/ldelf.go,
with a modification-deletion conflict.

Change-Id: Id2fcfd2094a31120966a6ea9c462b4ec76646b10

src/cmd/compile/internal/gc/main.go

@@ -525,7 +525,7 @@ func Main(archInit func(*Arch)) {
 	}
 	types.FmtLeft = int(FmtLeft)
 	types.FmtUnsigned = int(FmtUnsigned)
-	types.FErr = FErr
+	types.FErr = int(FErr)
 	types.Ctxt = Ctxt
 
 	initUniverse()