Use proper register on non-iOS Mach aarch64
diff --git a/rpmalloc/rpmalloc.c b/rpmalloc/rpmalloc.c
index fa4e025..2ea2ddc 100644
--- a/rpmalloc/rpmalloc.c
+++ b/rpmalloc/rpmalloc.c
@@ -706,15 +706,17 @@
uintptr_t tid;
# if defined(__i386__)
__asm__("movl %%gs:0, %0" : "=r" (tid) : : );
-# elif defined(__MACH__) && !TARGET_OS_IPHONE && !TARGET_OS_SIMULATOR
- __asm__("movq %%gs:0, %0" : "=r" (tid) : : );
# elif defined(__x86_64__)
+# if defined(__MACH__) && !TARGET_OS_IPHONE && !TARGET_OS_SIMULATOR
+ __asm__("movq %%gs:0, %0" : "=r" (tid) : : );
+# else
__asm__("movq %%fs:0, %0" : "=r" (tid) : : );
+# endif
# elif defined(__arm__)
__asm__ volatile ("mrc p15, 0, %0, c13, c0, 3" : "=r" (tid));
# elif defined(__aarch64__)
# if defined(__MACH__)
- // tpidr_el0 likely unused, always return 0 on iOs
+ // tpidr_el0 likely unused, always return 0 on iOS
__asm__ volatile ("mrs %0, tpidrro_el0" : "=r" (tid));
# else
__asm__ volatile ("mrs %0, tpidr_el0" : "=r" (tid));
