cmd/compile: fix buglet/typo in DWARF x86 setup

Fix typo in DWARF register config for GOOARCH=x86; was
picking up the AMD64 set, should have been selecting
x86 set.

Change-Id: I9a4c6f1378baf3cb2f0ad8d60f3ee2f24cd5dc91
Reviewed-on: https://go-review.googlesource.com/77990
Run-TryBot: Than McIntosh <thanm@google.com>
Reviewed-by: Heschi Kreinick <heschi@google.com>

src/cmd/internal/obj/x86/obj6.go

@@ -322,7 +322,7 @@ func rewriteToUseGot(ctxt *obj.Link, p *obj.Prog, newprog obj.ProgAlloc) {
 		//     $LEA $offset($reg), $reg
 		//     CALL $reg
 		// (we use LEAx rather than ADDx because ADDx clobbers
-		// flags and duffzero on 386 does not otherwise do so)
+		// flags and duffzero on 386 does not otherwise do so).
 		var sym *obj.LSym
 		if p.As == obj.ADUFFZERO {
 			sym = ctxt.Lookup("runtime.duffzero")
@@ -1260,5 +1260,5 @@ var Link386 = obj.LinkArch{
 	Assemble:       span6,
 	Progedit:       progedit,
 	UnaryDst:       unaryDst,
-	DWARFRegisters: AMD64DWARFRegisters,
+	DWARFRegisters: X86DWARFRegisters,
 }