[glibc/google/grte/v5-2.27/master] Make mutex hints gcc-only, improve a type in __arch_compare_and_exchange_bool_32_acq

[Fangrui Song <maskray@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=bb112e11de05c57cbe8e6b8641e0fe6b44f6a98f

commit bb112e11de05c57cbe8e6b8641e0fe6b44f6a98f
Author: Stan Shebs <stanshebs@google.com>
Date:   Wed Sep 26 13:50:57 2018 -0700

    Make mutex hints gcc-only, improve a type in __arch_compare_and_exchange_bool_32_acq

Diff:
---
 sysdeps/powerpc/powerpc64/atomic-machine.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/sysdeps/powerpc/powerpc64/atomic-machine.h b/sysdeps/powerpc/powerpc64/atomic-machine.h
index 1f09c52bd2..a2c78480bc 100644
--- a/sysdeps/powerpc/powerpc64/atomic-machine.h
+++ b/sysdeps/powerpc/powerpc64/atomic-machine.h
@@ -25,7 +25,7 @@
     adjacent to the lock word after the Store Conditional and the hint
     should be false.  */
 
-#if defined _ARCH_PWR6 || defined _ARCH_PWR6X
+#if (defined _ARCH_PWR6 || defined _ARCH_PWR6X) && !defined __clang__
 # define MUTEX_HINT_ACQ	",1"
 # define MUTEX_HINT_REL	",0"
 #else
@@ -45,7 +45,7 @@
    value as unsigned.  So we explicitly clear the high 32 bits in oldval.  */
 #define __arch_compare_and_exchange_bool_32_acq(mem, newval, oldval) \
 ({									      \
-  unsigned int __tmp, __tmp2;						      \
+  unsigned int __tmp; unsigned long __tmp2;						\
   __asm __volatile ("   clrldi  %1,%1,32\n"				      \
 		    "1:	lwarx	%0,0,%2" MUTEX_HINT_ACQ "\n"	 	      \
 		    "	subf.	%0,%1,%0\n"				      \