Place no_sanitize address/memory attributes in a GCC-compliant way
(Cherry-pick commit
2914cbff from 'master' branch.)
Now the attributes precede the function prototypes (the format is:
<attribute> void f(void) <body>).
* mark.c (GC_mark_from, GC_push_all_eager): Move
GC_ATTR_NO_SANITIZE_ADDR, GC_ATTR_NO_SANITIZE_MEMORY attributes to the
beginning of the function prototype.
* mach_dep.c (GC_with_callee_saves_pushed): Likewise.
* mark.c [WRAP_MARK_SOME && PARALLEL_MARK] (GC_push_conditional_eager):
Likewise.