runtime: restore "goroutine in C code" message

In the 1.9 upgrade I took out the word "goroutine" from a traceback
    showing a goroutine running in C code, to let TestCgoNumGoroutine
    pass.  However, it turns out that some code is actually checking for
    that string; for example,
    https://github.com/grpc/grpc-go/blob/master/test/leakcheck/leakcheck.go#L44
    So keep the message the same, and change the test.
    
    Reviewed-on: https://go-review.googlesource.com/64850

From-SVN: r252991

gcc/go/gofrontend/MERGE

@@ -1,4 +1,4 @@
-be69546afcac182cc93c569bc96665f0ef72d66a
+5fb74cd7192123a9ea06dcae0d5d8d0b3538db8f
 
 The first line of this file holds the git revision number of the last
 merge done from the gofrontend repository.

libgo/go/runtime/testdata/testprogcgo/numgoroutine.go

@@ -75,6 +75,7 @@ func checkNumGoroutine(label string, want int) (string, bool) {
 	sbuf := make([]byte, 32<<10)
 	sbuf = sbuf[:runtime.Stack(sbuf, true)]
 	n = strings.Count(string(sbuf), "goroutine ")
+	n -= strings.Count(string(sbuf), "goroutine in C code")
 	if n != want {
 		fmt.Printf("%s Stack: want %d; got %d:\n%s\n", label, want, n, string(sbuf))
 		return "", false

libgo/go/runtime/traceback_gccgo.go

@@ -216,7 +216,7 @@ func tracebackothers(me *g) {
 			print("\tgoroutine running on other thread; stack unavailable\n")
 			printcreatedby(gp)
 		} else if readgstatus(gp)&^_Gscan == _Gsyscall {
-			print("\tin C code; stack unavailable\n")
+			print("\tgoroutine in C code; stack unavailable\n")
 			printcreatedby(gp)
 		} else {
 			gp.traceback = &tb