runtime: fix assembly syntax

    
    Some assembler doesn't accept ULL suffix. In fact the suffix
    is not really necessary. Drop it.
    
    Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/180217

From-SVN: r271883

gcc/go/gofrontend/MERGE

-4150db0e4613043e38a146a971e5b0dcacad7c2a
+2e623bff8a5855bb6268c69bb04eb37cac8f2dc2
 
 The first line of this file holds the git revision number of the last
 merge done from the gofrontend repository.

libgo/runtime/go-context.S

@@ -57,7 +57,7 @@ __go_makecontext:
 	addq	%rcx, %rdx
 
 	// Align the SP, and push a dummy return address.
-	andq	$~0xfULL, %rdx
+	andq	$~0xf, %rdx
 	subq	$8, %rdx
 	movq	$0, (%rdx)