Revert r290839 - Fix configuring and building libc++ w/o an ABI library

llvm-svn: 290841
Cr-Mirrored-From: sso://chromium.googlesource.com/_direct/external/github.com/llvm/llvm-project
Cr-Mirrored-Commit: 221596df3336a45d635b63293867fb1166a863ca
diff --git a/src/stdexcept.cpp b/src/stdexcept.cpp
index 3f33330..90d8a34 100644
--- a/src/stdexcept.cpp
+++ b/src/stdexcept.cpp
@@ -14,8 +14,7 @@
 #include "__refstring"
 
 /* For _LIBCPPABI_VERSION */
-#if !defined(_LIBCPP_BUILDING_HAS_NO_ABI_LIBRARY) && \
-    (defined(LIBCXX_BUILDING_LIBCXXABI) || defined(__APPLE__) || defined(LIBCXXRT))
+#if defined(LIBCXX_BUILDING_LIBCXXABI) || defined(__APPLE__) || defined(LIBCXXRT)
 #include <cxxabi.h>
 #endif