When resolving a merge conflict, I put something inside an #ifdef. Fixed.

llvm-svn: 349181
Cr-Mirrored-From: sso://chromium.googlesource.com/_direct/external/github.com/llvm/llvm-project
Cr-Mirrored-Commit: cac3d118ae775647f432c2d0159eca562c486744
diff --git a/include/version b/include/version
index 552d663..d6ccb13 100644
--- a/include/version
+++ b/include/version
@@ -121,8 +121,8 @@
 #if _LIBCPP_STD_VER > 17
 #ifndef _LIBCPP_NO_HAS_CHAR8_T
 # define __cpp_lib_char8_t                              201811L
-#define  __cpp_lib_erase_if                             201811L
 #endif
+#define  __cpp_lib_erase_if                             201811L
 #endif
 
 #endif  // _LIBCPP_VERSIONH