Use EXPECT for checking various 'initialized' boolean variables

Use EXPECT for checking various 'initialized' boolean variables

* alloc.c (GC_try_to_collect_general, GC_expand_hp): Use "expect true"
for GC_is_initialized value.
* gcj_mlc.c (maybe_finalize): Likewise.
* malloc.c (GC_alloc_large, GC_generic_malloc_inner, malloc): Likewise.
* mallocx.c (GC_generic_malloc_many): Likewise.
* mark_rts.c (GC_add_roots, GC_clear_roots): Likewise.
* misc.c (GC_base, GC_init): Likewise.
* ptr_chck.c (GC_same_obj, GC_is_valid_displacement, GC_is_visible):
Likewise.
* darwin_stop_world.c (GC_push_all_stacks): Use "expect true"
for GC_thr_initialized value.
* pthread_stop_world.c (GC_push_all_stacks): Likewise.
* pthread_support.c (pthread_create): Likewise.
* dyn_load.c (GC_register_dynamic_libraries_dl_iterate_phdr): Use
"expect true" for excluded_segs value.
* include/private/gc_priv.h (COND_DUMP): Use "expect false"
for GC_dump_regularly value.
* malloc.c (GC_generic_malloc): Use "expect false" for GC_have_errors
value.
* mallocx.c (GC_generic_malloc_ignore_off_page,
GC_generic_malloc_many): Likewise.
* malloc.c (calloc): Use "expect true" for lib_bounds_set value.
* os_dep.c (GC_unix_mmap_get_mem): Use "expect true" for "initialized"
value.
* pthread_stop_world.c (GC_nacl_initialize_gc_thread): Use
"expect true" for GC_nacl_thread_parking_inited value.
* pthread_support.c (INIT_REAL_SYMS): Use "expect true" for
GC_syms_initialized value; remove redundant trailing ';'.
* pthread_support.c (GC_new_thread):  Use "expect true" for
first_thread_used value.
* win32_threads.c (GC_new_thread): Likewise.
* pthread_support.c (pthread_create): Use "expect true" for
parallel_initialized value.
* win32_threads.c (GC_CreateThread, GC_beginthreadex,
GC_pthread_join, GC_pthread_create, GC_pthread_sigmask,
GC_pthread_detach): Likewise.
* pthread_support.c (pthread_create): Use "expect false" for "si"
value to be NULL.
* thread_local_alloc.c (GC_init_thread_local): Use "expect true" for
keys_initialized value.
* typd_mlc.c (GC_make_descriptor): Use "expect true" for
GC_explicit_typing_initialized value.