[dev.ssa] cmd/compile: add pxor to list of instructions analyzeable by liveness analysis

Change-Id: I6ea0a3482d8813b8555b16fe6c377cad33554619
Reviewed-on: https://go-review.googlesource.com/14247Reviewed-by: David Chase <drchase@google.com>

src/cmd/compile/internal/amd64/prog.go

@@ -165,6 +165,7 @@ var progtable = [x86.ALAST]obj.ProgInfo{
 	x86.AORW:      {Flags: gc.SizeW | gc.LeftRead | RightRdwr | gc.SetCarry},
 	x86.APOPQ:     {Flags: gc.SizeQ | gc.RightWrite},
 	x86.APUSHQ:    {Flags: gc.SizeQ | gc.LeftRead},
+	x86.APXOR:     {Flags: gc.SizeD | gc.LeftRead | RightRdwr},
 	x86.ARCLB:     {Flags: gc.SizeB | gc.LeftRead | RightRdwr | gc.ShiftCX | gc.SetCarry | gc.UseCarry},
 	x86.ARCLL:     {Flags: gc.SizeL | gc.LeftRead | RightRdwr | gc.ShiftCX | gc.SetCarry | gc.UseCarry},
 	x86.ARCLQ:     {Flags: gc.SizeQ | gc.LeftRead | RightRdwr | gc.ShiftCX | gc.SetCarry | gc.UseCarry},

src/cmd/compile/internal/x86/prog.go

@@ -187,6 +187,7 @@ var progtable = [x86.ALAST]obj.ProgInfo{
 	x86.AORW:      {Flags: gc.SizeW | gc.LeftRead | RightRdwr | gc.SetCarry},
 	x86.APOPL:     {Flags: gc.SizeL | gc.RightWrite},
 	x86.APUSHL:    {Flags: gc.SizeL | gc.LeftRead},
+	x86.APXOR:     {Flags: gc.SizeD | gc.LeftRead | RightRdwr},
 	x86.ARCLB:     {Flags: gc.SizeB | gc.LeftRead | RightRdwr | gc.ShiftCX | gc.SetCarry | gc.UseCarry},
 	x86.ARCLL:     {Flags: gc.SizeL | gc.LeftRead | RightRdwr | gc.ShiftCX | gc.SetCarry | gc.UseCarry},
 	x86.ARCLW:     {Flags: gc.SizeW | gc.LeftRead | RightRdwr | gc.ShiftCX | gc.SetCarry | gc.UseCarry},