[libcxx] Use local names for the operator new impl symbols

This way the impl symbols don't even make it into the symbol table which
is important for symbolization since we want the symbolizer to always
pick up the public symbol (which has the same address as the impl one).

Author: petrhosek

libcxx/src/include/overridable_function.h

@@ -90,8 +90,8 @@ _LIBCPP_END_NAMESPACE_STD
 
 #  define _LIBCPP_CAN_DETECT_OVERRIDDEN_FUNCTION 1
 #  define _LIBCPP_OVERRIDABLE_FUNCTION(symbol, type, name, arglist)                                                    \
-    static type symbol##_impl__ arglist __asm__(_LIBCPP_TOSTRING(symbol##_impl__));                                    \
-    [[gnu::weak, gnu::alias(_LIBCPP_TOSTRING(symbol##_impl__))]] type name arglist;                                    \
+    static type symbol##_impl__ arglist __asm__(".L" _LIBCPP_TOSTRING(symbol));                                        \
+    [[gnu::weak, gnu::alias(".L" _LIBCPP_TOSTRING(symbol))]] type name arglist;                                        \
     _LIBCPP_BEGIN_NAMESPACE_STD                                                                                        \
     template <>                                                                                                        \
     inline bool __is_function_overridden<static_cast<type(*) arglist>(name)>() {                                       \