[libc++abi] Fix unused function when building with LIBCXXABI_SILENT_TERMINATE

[thomasanderson]

Summary

This fixes:
src/cxa_default_handlers.cpp:25:13: error: unused function 'demangling_terminate_handler' [-Werror,-Wunused-function]

[thomasanderson]

thakis@ ptal and land if lg

[pcc]

Adding more reviewers.

[pcc]

src/cxa_default_handlers.cpp

80 ↗

(On Diff #130983)

I think this needs to be moved to line 24.

[pcc]

LGTM

libcxxabi/trunk/src/cxa_default_handlers.cpp

 #include <exception>
 #include <cstdlib>
 #include "abort_message.h"
 #include "cxxabi.h"
 #include "cxa_handlers.hpp"
 #include "cxa_exception.hpp"
 #include "private_typeinfo.h"
 
+#if !defined(LIBCXXABI_SILENT_TERMINATE)
 static const char* cause = "uncaught";
 
 __attribute__((noreturn))
 static void demangling_terminate_handler()
 {
     // If there might be an uncaught exception
     using namespace __cxxabiv1;
     __cxa_eh_globals* globals = __cxa_get_globals_fast();

 
 __attribute__((noreturn))
 static void demangling_unexpected_handler()
 {
     cause = "unexpected";
     std::terminate();
 }
 
-#if !defined(LIBCXXABI_SILENT_TERMINATE)
 static std::terminate_handler default_terminate_handler = demangling_terminate_handler;
 static std::terminate_handler default_unexpected_handler = demangling_unexpected_handler;
 #else
 static std::terminate_handler default_terminate_handler = std::abort;
 static std::terminate_handler default_unexpected_handler = std::terminate;
 #endif
 
 //