Adjust code indentation of malloc/calloc/str[n]dup

Adjust code indentation of malloc/calloc/str[n]dup
(and do not define GC_init_lib_bounds if unused)

* malloc.c (GC_debug_malloc_replacement): Do not define/undefine macro
if REDIRECT_MALLOC_IN_HEADER.
* malloc.c (GC_libpthread_start, GC_libpthread_start,
GC_libpthread_end, GC_libld_start, GC_init_lib_bounds): Do not define
if REDIRECT_MALLOC_IN_HEADER.
* malloc.c (GC_debug_malloc_replacement, malloc, GC_init_lib_bounds,
calloc, strdup, strndup, free): Reformat code (adjust indentation) and
comments.
* malloc (free): Do not call GC_free if IGNORE_FREE defined.

Conflicts:

	malloc.c