Merge a few minor config tweaks from Trunk

[SVN r63470]

include/boost/config/compiler/clang.hpp

@@ -53,13 +53,6 @@
 // them is wrong.
 #define BOOST_NO_EXTERN_TEMPLATE
 
-// Clang version 2.0 (trunk 103769) does not yet properly 
-// value-initialize objects of a pointer-to-member type,
-// as was reported by Christopher Jefferson in May 2010, Bug 7139,
-// "ptr to member not zeroed", http://llvm.org/bugs/show_bug.cgi?id=7139
-// (Niels Dekker, LKEB, May 2010)
-#define BOOST_NO_COMPLETE_VALUE_INITIALIZATION
-
 #ifndef BOOST_COMPILER
 #  define BOOST_COMPILER "Clang version " __clang_version__
 #endif

include/boost/config/compiler/gcc.hpp

@@ -135,8 +135,12 @@
 //
 #if __GNUC__ * 100 + __GNUC_MINOR__ >= 403
 #  ifndef __GXX_RTTI
-#     define BOOST_NO_TYPEID
-#     define BOOST_NO_RTTI
+#     ifndef BOOST_NO_TYPEID
+#        define BOOST_NO_TYPEID
+#     endif
+#     ifndef BOOST_NO_RTTI
+#        define BOOST_NO_RTTI
+#     endif
 #  endif
 #endif
 

include/boost/config/compiler/visualc.hpp

@@ -68,7 +68,6 @@
 #  define BOOST_NO_POINTER_TO_MEMBER_TEMPLATE_PARAMETERS
 #  define BOOST_NO_IS_ABSTRACT
 #  define BOOST_NO_FUNCTION_TYPE_SPECIALIZATIONS
-#  define BOOST_NO_EXTERN_TEMPLATE
 // TODO: what version is meant here? Have there really been any fixes in cl 12.01 (as e.g. shipped with eVC4)?
 #  if (_MSC_VER > 1200)
 #     define BOOST_NO_MEMBER_FUNCTION_SPECIALIZATIONS

include/boost/config/platform/cygwin.hpp

@@ -8,9 +8,6 @@
 //  cygwin specific config options:
 
 #define BOOST_PLATFORM "Cygwin"
-#define BOOST_NO_CWCTYPE
-#define BOOST_NO_CWCHAR
-#define BOOST_NO_SWPRINTF
 #define BOOST_HAS_DIRENT_H
 #define BOOST_HAS_LOG1P
 #define BOOST_HAS_EXPM1