cmd/internal/obj/x86, cmd/internal/ld, cmd/6l: 6g/asm -dynlink accesses global data via a GOT

Change-Id: I49862e177045369d6c94d6a58afbdace4f13cc96
Reviewed-on: https://go-review.googlesource.com/8237
Reviewed-by: Ian Lance Taylor <iant@golang.org>

src/cmd/internal/obj/link.go

@@ -173,6 +173,9 @@ const (
 	NAME_STATIC
 	NAME_AUTO
 	NAME_PARAM
+	// A reference to name@GOT(SB) is a reference to the entry in the global offset
+	// table for 'name'.
+	NAME_GOTREF
 )
 
 const (
@@ -380,6 +383,7 @@ const (
 	R_PLT2
 	R_USEFIELD
 	R_POWER_TOC
+	R_GOTPCREL
 )
 
 type Auto struct {
@@ -431,6 +435,7 @@ type Link struct {
 	Debugdivmod        int32
 	Debugpcln          int32
 	Flag_shared        int32
+	Flag_dynlink       bool
 	Bso                *Biobuf
 	Pathname           string
 	Windows            int32