[libc++] Remove deprecated _LIBCPP_ALTERNATE_STRING_LAYOUT macro

We use the _LIBCPP_ABI_ALTERNATE_STRING_LAYOUT macro for that now instead.
I did leave a check behind to make sure that nobody was still using the old
macro name. I'll remove it a couple of months down the road.

diff --git a/libcxx/include/__config b/libcxx/include/__config
index 26fadcf..a0de82c 100644 (file)
--- a/libcxx/include/__config
+++ b/libcxx/include/__config
@@ -398,12 +398,12 @@
 
 #if defined(_LIBCPP_COMPILER_CLANG)
 
-// _LIBCPP_ALTERNATE_STRING_LAYOUT is an old name for
-// _LIBCPP_ABI_ALTERNATE_STRING_LAYOUT left here for backward compatibility.
-#if (defined(__APPLE__) && !defined(__i386__) && !defined(__x86_64__) &&       \
-     (!defined(__arm__) || __ARM_ARCH_7K__ >= 2)) ||                           \
-    defined(_LIBCPP_ALTERNATE_STRING_LAYOUT)
-#define _LIBCPP_ABI_ALTERNATE_STRING_LAYOUT
+#if defined(_LIBCPP_ALTERNATE_STRING_LAYOUT)
+#  error _LIBCPP_ALTERNATE_STRING_LAYOUT is deprecated, please use _LIBCPP_ABI_ALTERNATE_STRING_LAYOUT instead
+#endif
+#if defined(__APPLE__) && !defined(__i386__) && !defined(__x86_64__) &&       \
+    (!defined(__arm__) || __ARM_ARCH_7K__ >= 2)
+#  define _LIBCPP_ABI_ALTERNATE_STRING_LAYOUT
 #endif
 
 #if __has_feature(cxx_alignas)