[dev.link] cmd/compile: mark stmp and stkobj symbols as static

Mark compiler-generated ".stmp_%d" and "<fn>.stkobj" symbols as
AttrStatic, so as to tell the linker that they do not need to be
inserted into its name lookup tables.

Change-Id: I59ffd11659b2c54c2d0ad41275d05c3f919e3b88
Reviewed-on: https://go-review.googlesource.com/c/go/+/240497
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

src/cmd/internal/obj/plist.go

@@ -170,6 +170,9 @@ func (ctxt *Link) Globl(s *LSym, size int64, flag int) {
 	} else if flag&TLSBSS != 0 {
 		s.Type = objabi.STLSBSS
 	}
+	if strings.HasPrefix(s.Name, "\"\"."+StaticNamePref) {
+		s.Set(AttrStatic, true)
+	}
 }
 
 // EmitEntryLiveness generates PCDATA Progs after p to switch to the