Issue #2378 & #2051 - Part 4 - Remove unused moz_xposix_memalign().

Also switch to using HAVE_POSIX_MEMALIGN for Mac PowerPC tests.
When there is no posix_memalign() on Mac, just call malloc().

memory/mozalloc/mozalloc.cpp

@@ -129,17 +129,6 @@ moz_xstrndup(const char* str, size_t strsize)
 
 #if defined(HAVE_POSIX_MEMALIGN)
 int
-moz_xposix_memalign(void **ptr, size_t alignment, size_t size)
-{
-    int err = posix_memalign_impl(ptr, alignment, size);
-    if (MOZ_UNLIKELY(err && ENOMEM == err)) {
-        mozalloc_handle_oom(size);
-        return moz_xposix_memalign(ptr, alignment, size);
-    }
-    // else: (0 == err) or (EINVAL == err)
-    return err;
-}
-int
 moz_posix_memalign(void **ptr, size_t alignment, size_t size)
 {
     int code = posix_memalign_impl(ptr, alignment, size);

memory/mozalloc/mozalloc.h

@@ -87,9 +87,6 @@ MFBT_API char* moz_xstrndup(const char* str, size_t strsize)
 
 
 #if defined(HAVE_POSIX_MEMALIGN)
-MFBT_API __attribute__ ((warn_unused_result))
-int moz_xposix_memalign(void **ptr, size_t alignment, size_t size);
-
 MFBT_API __attribute__ ((warn_unused_result))
 int moz_posix_memalign(void **ptr, size_t alignment, size_t size);
 #endif /* if defined(HAVE_POSIX_MEMALIGN) */

memory/mozjemalloc/jemalloc.c

@@ -5869,7 +5869,11 @@ MOZ_MEMORY_API
 void *
 MEMALIGN(size_t alignment, size_t size)
 {
-#if defined(MOZ_MEMORY_DARWIN) && !defined(__ppc__)
+#if defined(MOZ_MEMORY_DARWIN) && !defined(HAVE_POSIX_MEMALIGN)
+	// If we don't have memalign, like on 10.5 just use malloc
+	// it should be 16 byte aligned and jemalloc is not enabled. 
+	return malloc(size);
+#else
 	DARWIN_ONLY(return (szone->memalign)(szone, alignment, size));
 #endif
 

memory/volatile/VolatileBufferOSX.cpp

@@ -47,7 +47,7 @@ VolatileBuffer::Init(size_t aSize, size_t aAlignment)
   }
 
 heap_alloc:
-#if !defined(__ppc__)
+#ifdef HAVE_POSIX_MEMALIGN
   (void)moz_posix_memalign(&mBuf, aAlignment, aSize);
 #else
   // 10.4 doesn't have memalign, but our malloc()s are always aligned to