libstdc++: avoid __GLIBCXX__ redefinition

testsuite/lib/dg-options.exp defines __GLIBCXX__ to 9999999; avoid a macro
redefinition warning in that case.

libstdc++-v3/ChangeLog:

	* include/bits/c++config: Avoid redefining __GLIBCXX__.

diff --git a/libstdc++-v3/include/bits/c++config b/libstdc++-v3/include/bits/c++config
index 0f0cc7cd659943ff0734380b2da8eac2ec8fd7d0..54d455be2266a87b2c54684baba952bda4afa6e3 100644 (file)
--- a/libstdc++-v3/include/bits/c++config
+++ b/libstdc++-v3/include/bits/c++config
@@ -36,6 +36,7 @@
 #define _GLIBCXX_RELEASE
 
 // The datestamp of the C++ library in compressed ISO date format.
+#undef __GLIBCXX__ /* The testsuite defines it to 99999999 to block PCH.  */
 #define __GLIBCXX__
 
 // Macros for various attributes.