Update to build on Xcode 6.0: turn BACK ON warnings as errors for overloaded...

Update to build on Xcode 6.0: turn BACK ON warnings as errors for overloaded virtuals [-Woverloaded-virtual] and fix up first (of many) files

indra/cmake/00-Common.cmake

@@ -213,7 +213,7 @@ if (LINUX OR DARWIN)
   set(GCC_WARNINGS "-Wall -Wno-sign-compare -Wno-trigraphs")
   elseif (CMAKE_COMPILER_IS_CLANGXX)
     # These unused warnings really ought to be cleaned up over time
-    set(UNUSED_WARNINGS "-Wno-overloaded-virtual")
+    # set(UNUSED_WARNINGS "-Wno-overloaded-virtual")
     set(GCC_WARNINGS "-Wall -Wno-sign-compare -Wno-trigraphs ${UNUSED_WARNINGS}")
   endif()
 

indra/llcommon/llfile.cpp

@@ -807,7 +807,7 @@ std::streamsize llstdio_filebuf::xsgetn(char_type* __s, std::streamsize __n)
 	return __ret;
 }
 
-std::streamsize llstdio_filebuf::xsputn(char_type* __s, std::streamsize __n)
+std::streamsize llstdio_filebuf::xsputn(const char_type* __s, std::streamsize __n)
 {
 	// Optimization in the always_noconv() case, to be generalized in the
 	// future: when __n is sufficiently large we write directly instead of

indra/llcommon/llfile.h

@@ -188,7 +188,7 @@ class LL_COMMON_API llstdio_filebuf : public _Myfb
 	/*virtual*/ int sync();
 
 	std::streamsize xsgetn(char_type*, std::streamsize);
-	std::streamsize xsputn(char_type*, std::streamsize);
+	std::streamsize xsputn(const char_type*, std::streamsize);
 #endif
 };