libstdc++: use extern "C++" in all our C++ system headers.

This is needed to build an independent toolchain with g++ that doesn't think
that all these headers are in C.

Change-Id: Ie9a8ccfcab7780d6a4e5722777d61c2b1b312001

libstdc++/include/cctype

@@ -36,6 +36,8 @@
 
 #include <ctype.h>
 
+extern "C++" {
+
 namespace std 
 {
 using ::isalnum;
@@ -53,4 +55,6 @@ using ::tolower;
 using ::toupper;
 }  // namespace std
 
+}  // extern C++
+
 #endif  // BIONIC_LIBSTDCPP_INCLUDE_CCTYPE__

libstdc++/include/cmath

@@ -37,6 +37,8 @@
 #include <cstddef>
 #include <math.h>
 
+extern "C++" {
+
 namespace std
 {
 // Functions.
@@ -68,4 +70,6 @@ using ::floor;
 using ::fmod;
 }  // namespace std
 
+}  // extern C++
+
 #endif  // BIONIC_LIBSTDCPP_INCLUDE_CMATH__

libstdc++/include/csetjmp

@@ -36,6 +36,8 @@
 
 #include <setjmp.h>
 
+extern "C++" {
+
 #ifndef setjmp
 #define setjmp(env) setjmp (env)
 #endif
@@ -46,4 +48,6 @@ using ::jmp_buf;
 using ::longjmp;
 }  // namespace std
 
+}  // extern C++
+
 #endif  // BIONIC_LIBSTDCPP_INCLUDE_CSETJMP__

libstdc++/include/csignal

@@ -36,6 +36,8 @@
 
 #include <signal.h>
 
+extern "C++" {
+
 namespace std
 {
 using ::sig_atomic_t;
@@ -43,4 +45,6 @@ using ::signal;
 using ::raise;
 }  // namespace std
 
+}  // extern C++
+
 #endif  // BIONIC_LIBSTDCPP_INCLUDE_CSIGNAL__

libstdc++/include/cstddef

@@ -38,9 +38,13 @@
  */
 #include <stddef.h>
 
+extern "C++" {
+
 namespace std {
 using ::ptrdiff_t;
 using ::size_t;
 }  // namespace std
 
+}  // extern C++
+
 #endif  // BIONIC_LIBSTDCPP_INCLUDE_CSTDDEF__

libstdc++/include/cstdio

@@ -36,6 +36,8 @@
 #include <cstddef>
 #include <stdio.h>
 
+extern "C++" {
+
 namespace std {
 using ::FILE;
 using ::fpos_t;
@@ -89,4 +91,6 @@ using ::vsnprintf;
 using ::vsscanf;
 }  // namespace std
 
+}  // extern C++
+
 #endif  // BIONIC_LIBSTDCPP_INCLUDE_CSTDIO__

libstdc++/include/cstdlib

@@ -35,6 +35,8 @@
  */
 #include <stdlib.h>
 
+extern "C++" {
+
 namespace std {
 
 using ::exit;
@@ -110,4 +112,6 @@ using ::wctomb;
 using ::wcstombs;
 }  // namespace std
 
+}  // extern C++
+
 #endif  // BIONIC_LIBSTDCPP_INCLUDE_CSTDLIB__

libstdc++/include/cstring

@@ -37,6 +37,8 @@
 #include <cstddef>
 #include <string.h>
 
+extern "C++" {
+
 namespace std
 {
 using ::memchr;
@@ -63,4 +65,6 @@ using ::strtok;
 using ::strxfrm;
 }  // namespace std
 
+}  // extern C++
+
 #endif  // BIONIC_LIBSTDCPP_INCLUDE_CSTRING__

libstdc++/include/ctime

@@ -37,6 +37,8 @@
 #include <cstddef>
 #include <time.h>
 
+extern "C++" {
+
 namespace std 
 {
 // Types.
@@ -56,4 +58,6 @@ using ::localtime;
 using ::strftime;
 }  // namespace std
 
+}  // extern C++
+
 #endif  // BIONIC_LIBSTDCPP_INCLUDE_CTIME__

libstdc++/include/new

@@ -4,6 +4,8 @@
 
 #include <cstddef>
 
+extern "C++" {
+
 namespace std {
     struct nothrow_t {};
     extern const nothrow_t nothrow;
@@ -25,4 +27,6 @@ inline void* operator new[](std::size_t, void* p) { return p; }
 inline void  operator delete(void*, void*) { }
 inline void  operator delete[](void*, void*) { }
 
+}  // extern C++
+
 #endif // __NEW__

libstdc++/include/typeinfo

@@ -1,6 +1,7 @@
 #ifndef _TYPEINFO_HEADER_GAURD
 #define _TYPEINFO_HEADER_GAURD
 
+extern "C++" {
 
 namespace std {
     class type_info;
@@ -25,4 +26,6 @@ private:
     type_info & operator=(type_info const & right);
 };
 
+}  // C++
+
 #endif