cmd/compile: eliminate some Linksym calls in obj.go

Passes toolstash-check.

Change-Id: I0cb2ea9ca7ec2449999af28457270ff7b3324e92
Reviewed-on: https://go-review.googlesource.com/41410
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>

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

@@ -221,9 +221,9 @@ func dumpglobls() {
 	}
 
 	for _, s := range funcsyms {
-		sf := s.Pkg.Lookup(funcsymname(s))
-		dsymptr(sf.Linksym(), 0, s.Linksym(), 0)
-		ggloblsym(sf.Linksym(), int32(Widthptr), obj.DUPOK|obj.RODATA)
+		sf := s.Pkg.Lookup(funcsymname(s)).Linksym()
+		dsymptr(sf, 0, s.Linksym(), 0)
+		ggloblsym(sf, int32(Widthptr), obj.DUPOK|obj.RODATA)
 	}
 
 	// Do not reprocess funcsyms on next dumpglobls call.
@@ -324,16 +324,18 @@ func slicebytes(nam *Node, s string, len int) {
 	sym := localpkg.Lookup(symname)
 	sym.Def = asTypesNode(newname(sym))
 
-	off := dsname(sym.Linksym(), 0, s)
-	ggloblsym(sym.Linksym(), int32(off), obj.NOPTR|obj.LOCAL)
+	lsym := sym.Linksym()
+	off := dsname(lsym, 0, s)
+	ggloblsym(lsym, int32(off), obj.NOPTR|obj.LOCAL)
 
 	if nam.Op != ONAME {
 		Fatalf("slicebytes %v", nam)
 	}
+	nsym := nam.Sym.Linksym()
 	off = int(nam.Xoffset)
-	off = dsymptr(nam.Sym.Linksym(), off, sym.Linksym(), 0)
-	off = duintptr(nam.Sym.Linksym(), off, uint64(len))
-	duintptr(nam.Sym.Linksym(), off, uint64(len))
+	off = dsymptr(nsym, off, lsym, 0)
+	off = duintptr(nsym, off, uint64(len))
+	duintptr(nsym, off, uint64(len))
 }
 
 func dsname(s *obj.LSym, off int, t string) int {