remove __MALLOC_GLIBC_COMPAT__ option

This option is enabled for a long time and I see no
useful case where we should be incompatible to glibc here.

extra/Configs/Config.in

@@ -610,23 +610,6 @@ config MALLOC_STANDARD
 
 endchoice
 
-config MALLOC_GLIBC_COMPAT
-	bool "Malloc returns live pointer for malloc(0)"
-	help
-	  The behavior of malloc(0) is listed as implementation-defined by
-	  SuSv3.  Glibc returns a valid pointer to something, while uClibc
-	  normally returns NULL.  I personally feel glibc's behavior is
-	  not particularly safe, and allows buggy applications to hide very
-	  serious problems.
-
-	  When this option is enabled, uClibc will act just like glibc, and
-	  return a live pointer when someone calls malloc(0).  This pointer
-	  provides a malloc'ed area with a size of 1 byte.  This feature is
-	  mostly useful when dealing with applications using autoconf's broken
-	  AC_FUNC_MALLOC macro (which redefines malloc as rpl_malloc if it
-	  does not detect glibc style returning-a-valid-pointer-for-malloc(0)
-	  behavior).  Most people can safely answer N.
-
 config UCLIBC_HAS_OBSTACK
 	bool "Obstack Support (gnu extension)"
 	help

libc/stdlib/malloc-simple/alloc.c

@@ -25,13 +25,7 @@ void *malloc(size_t size)
 	void *result;
 
 	if (unlikely(size == 0)) {
-#if defined(__MALLOC_GLIBC_COMPAT__)
 		size++;
-#else
-		/* Some programs will call malloc (0).  Lets be strict and return NULL */
-		__set_errno(ENOMEM);
-		return NULL;
-#endif
 	}
 
 #ifdef __ARCH_USE_MMU__

libc/stdlib/malloc-standard/malloc.c

@@ -825,13 +825,6 @@ void* malloc(size_t bytes)
     void *          sysmem;
     void *          retval;
 
-#if !defined(__MALLOC_GLIBC_COMPAT__)
-    if (!bytes) {
-        __set_errno(ENOMEM);
-        return NULL;
-    }
-#endif
-
     /*
        Convert request size to internal form by adding (sizeof(size_t)) bytes
        overhead plus possibly more to obtain necessary alignment and/or

libc/stdlib/malloc/malloc.c

@@ -208,14 +208,8 @@ malloc (size_t size)
     __heap_check (__malloc_heap, "malloc");
 #endif
 
-#ifdef __MALLOC_GLIBC_COMPAT__
   if (unlikely (size == 0))
     size++;
-#else
-  /* Some programs will call malloc (0).  Lets be strict and return NULL */
-  if (unlikely (size == 0))
-    goto oom;
-#endif
 
   /* Check if they are doing something dumb like malloc(-1) */
   if (unlikely(((unsigned long)size > (unsigned long)(MALLOC_HEADER_SIZE*-2))))