Workaround 'local address assignment to a global variable' CSA warning

Workaround 'local address assignment to a global variable' CSA warning

* include/gc.h [(!__GNUC__ || __INTEL_COMPILER) && LINT2]
(GC_reachable_here): Transform ptr in the same way as COVERT_DATAFLOW()
does.
* mach_dep.c (GC_with_callee_saves_pushed): Transform the argument of
GC_noop1() by COVERT_DATAFLOW().
* misc.c [!ASM_CLEAR_CODE] (GC_clear_stack_inner): Likewise.
* misc.c (GC_call_with_stack_base, GC_call_with_gc_active): Likewise.
* pthread_support.c (GC_call_with_gc_active): Likewise.
* win32_threads.c (GC_call_with_gc_active): Likewise.
* misc.c (GC_call_with_gc_active): Transform &stacksect by
COVERT_DATAFLOW() when storing to GC_stackbottom.
* pthread_support.c (GC_call_with_gc_active): Likewise.