cmd/go: correct gccgo buildid file on ARM

    
    Bring in https://golang.org/cl/135297 from the gc repository to fix a
    GCC bug report.
    
    Original CL description:
    
        The GNU assembler for ARM treats @ as a comment character, so section
        types must be written using % instead.
    
        Fixes https://gcc.gnu.org/PR87260.
    
    Reviewed-on: https://go-review.googlesource.com/135360

From-SVN: r264330

gcc/go/gofrontend/MERGE

-3fd61802286c81e5fb672f682d9e661181184d1f
+92a14213215fd93df7240fa9d376a1213b1d5a74
 
 The first line of this file holds the git revision number of the last
 merge done from the gofrontend repository.

libgo/go/cmd/go/internal/work/buildid.go

@@ -337,8 +337,12 @@ func (b *Builder) gccgoBuildIDELFFile(a *Action) (string, error) {
 	}
 	fmt.Fprintf(&buf, "\n")
 	if cfg.Goos != "solaris" {
-		fmt.Fprintf(&buf, "\t"+`.section .note.GNU-stack,"",@progbits`+"\n")
-		fmt.Fprintf(&buf, "\t"+`.section .note.GNU-split-stack,"",@progbits`+"\n")
+		secType := "@progbits"
+		if cfg.Goarch == "arm" {
+			secType = "%progbits"
+		}
+		fmt.Fprintf(&buf, "\t"+`.section .note.GNU-stack,"",%s`+"\n", secType)
+		fmt.Fprintf(&buf, "\t"+`.section .note.GNU-split-stack,"",%s`+"\n", secType)
 	}
 
 	if cfg.BuildN || cfg.BuildX {