cmd/gc: fix handling of append with -race.

Also re-enable race tests in run.bash.

Fixes #7334.

LGTM=rsc
R=rsc, dvyukov, iant, bradfitz, dave
CC=golang-codereviews
https://golang.org/cl/65740043

src/cmd/gc/walk.c

@@ -2707,9 +2707,10 @@ appendslice(Node *n, NodeList **init)
 			fn = syslook("copy", 1);
 		argtype(fn, l1->type);
 		argtype(fn, l2->type);
-		l = list(l, mkcall1(fn, types[TINT], init,
+		nt = mkcall1(fn, types[TINT], &l,
 				nptr1, nptr2,
-				nodintconst(s->type->type->width)));
+				nodintconst(s->type->type->width));
+		l = list(l, nt);
 	} else {
 		// memmove(&s[len(l1)], &l2[0], len(l2)*sizeof(T))
 		nptr1 = nod(OINDEX, s, nod(OLEN, l1, N));
@@ -2724,7 +2725,8 @@ appendslice(Node *n, NodeList **init)
 
 		nwid = cheapexpr(conv(nod(OLEN, l2, N), types[TUINTPTR]), &l);
 		nwid = nod(OMUL, nwid, nodintconst(s->type->type->width));
-		l = list(l, mkcall1(fn, T, init, nptr1, nptr2, nwid));
+		nt = mkcall1(fn, T, &l, nptr1, nptr2, nwid);
+		l = list(l, nt);
 	}
 
 	// s = s[:len(l1)+len(l2)]

src/run.bash

@@ -57,10 +57,8 @@ go test sync -short -timeout=$(expr 120 \* $timeout_scale)s -cpu=10
 
 # Race detector only supported on Linux and OS X,
 # and only on amd64, and only when cgo is enabled.
-# Disabled due to golang.org/issue/7334; remove XXX below
-# and in run.bat to reenable.
 case "$GOHOSTOS-$GOOS-$GOARCH-$CGO_ENABLED" in
-XXXlinux-linux-amd64-1 | XXXdarwin-darwin-amd64-1)
+linux-linux-amd64-1 | darwin-darwin-amd64-1)
 	echo
 	echo '# Testing race detector.'
 	go test -race -i runtime/race flag
@@ -175,7 +173,7 @@ rm -f goplay
 
 [ "$GOARCH" == arm ] ||
 (xcd ../test/bench/shootout
-./timing.sh -test || exit 1
+time ./timing.sh -test || exit 1
 ) || exit $?
 
 [ "$GOOS" == openbsd ] || # golang.org/issue/5057

src/run.bat

@@ -54,9 +54,7 @@ echo.
 
 :: Race detector only supported on Linux and OS X,
 :: and only on amd64, and only when cgo is enabled.
-:: Disabled due to golang.org/issue/7334; remove XXX below
-:: and in run.bash to reenable.
-if not "%GOHOSTOS%-%GOOS%-%GOARCH%-%CGO_ENABLED%" == "XXXwindows-windows-amd64-1" goto norace
+if not "%GOHOSTOS%-%GOOS%-%GOARCH%-%CGO_ENABLED%" == "windows-windows-amd64-1" goto norace
 echo # Testing race detector.
 go test -race -i runtime/race flag
 if errorlevel 1 goto fail