[libc++abi] Avoid using deprecated throw specifications in >= C++11 (#109296)

Closes #108426

Author: ldionne

libcxxabi/include/__cxxabi_config.h

@@ -103,4 +103,10 @@
 #define _LIBCXXABI_DTOR_FUNC
 #endif
 
+#if __cplusplus < 201103L
+#  define _LIBCXXABI_NOEXCEPT throw()
+#else
+#  define _LIBCXXABI_NOEXCEPT noexcept
+#endif
+
 #endif // ____CXXABI_CONFIG_H

libcxxabi/include/cxxabi.h

@@ -43,16 +43,16 @@ extern "C"  {
 
 // 2.4.2 Allocating the Exception Object
 extern _LIBCXXABI_FUNC_VIS void *
-__cxa_allocate_exception(size_t thrown_size) throw();
+__cxa_allocate_exception(size_t thrown_size) _LIBCXXABI_NOEXCEPT;
 extern _LIBCXXABI_FUNC_VIS void
-__cxa_free_exception(void *thrown_exception) throw();
+__cxa_free_exception(void *thrown_exception) _LIBCXXABI_NOEXCEPT;
 // This function is an LLVM extension, which mirrors the same extension in libsupc++ and libcxxrt
 extern _LIBCXXABI_FUNC_VIS __cxa_exception*
 #ifdef __wasm__
 // In Wasm, a destructor returns its argument
-__cxa_init_primary_exception(void* object, std::type_info* tinfo, void*(_LIBCXXABI_DTOR_FUNC* dest)(void*)) throw();
+__cxa_init_primary_exception(void* object, std::type_info* tinfo, void*(_LIBCXXABI_DTOR_FUNC* dest)(void*)) _LIBCXXABI_NOEXCEPT;
 #else
-__cxa_init_primary_exception(void* object, std::type_info* tinfo, void(_LIBCXXABI_DTOR_FUNC* dest)(void*)) throw();
+__cxa_init_primary_exception(void* object, std::type_info* tinfo, void(_LIBCXXABI_DTOR_FUNC* dest)(void*)) _LIBCXXABI_NOEXCEPT;
 #endif
 
 // 2.4.3 Throwing the Exception Object
@@ -66,21 +66,21 @@ __cxa_throw(void *thrown_exception, std::type_info *tinfo,
 
 // 2.5.3 Exception Handlers
 extern _LIBCXXABI_FUNC_VIS void *
-__cxa_get_exception_ptr(void *exceptionObject) throw();
+__cxa_get_exception_ptr(void *exceptionObject) _LIBCXXABI_NOEXCEPT;
 extern _LIBCXXABI_FUNC_VIS void *
-__cxa_begin_catch(void *exceptionObject) throw();
+__cxa_begin_catch(void *exceptionObject) _LIBCXXABI_NOEXCEPT;
 extern _LIBCXXABI_FUNC_VIS void __cxa_end_catch();
 #if defined(_LIBCXXABI_ARM_EHABI)
 extern _LIBCXXABI_FUNC_VIS bool
-__cxa_begin_cleanup(void *exceptionObject) throw();
+__cxa_begin_cleanup(void *exceptionObject) _LIBCXXABI_NOEXCEPT;
 extern _LIBCXXABI_FUNC_VIS void __cxa_end_cleanup();
 #endif
 extern _LIBCXXABI_FUNC_VIS std::type_info *__cxa_current_exception_type();
 
 // GNU extension
 // Calls `terminate` with the current exception being caught. This function is used by GCC when a `noexcept` function
 // throws an exception inside a try/catch block and doesn't catch it.
-extern _LIBCXXABI_FUNC_VIS _LIBCXXABI_NORETURN void __cxa_call_terminate(void*) throw();
+extern _LIBCXXABI_FUNC_VIS _LIBCXXABI_NORETURN void __cxa_call_terminate(void*) _LIBCXXABI_NOEXCEPT;
 
 // 2.5.4 Rethrowing Exceptions
 extern _LIBCXXABI_FUNC_VIS _LIBCXXABI_NORETURN void __cxa_rethrow();
@@ -168,23 +168,23 @@ extern _LIBCXXABI_FUNC_VIS char *__cxa_demangle(const char *mangled_name,
 
 // Apple additions to support C++ 0x exception_ptr class
 // These are primitives to wrap a smart pointer around an exception object
-extern _LIBCXXABI_FUNC_VIS void *__cxa_current_primary_exception() throw();
+extern _LIBCXXABI_FUNC_VIS void *__cxa_current_primary_exception() _LIBCXXABI_NOEXCEPT;
 extern _LIBCXXABI_FUNC_VIS void
 __cxa_rethrow_primary_exception(void *primary_exception);
 extern _LIBCXXABI_FUNC_VIS void
-__cxa_increment_exception_refcount(void *primary_exception) throw();
+__cxa_increment_exception_refcount(void *primary_exception) _LIBCXXABI_NOEXCEPT;
 extern _LIBCXXABI_FUNC_VIS void
-__cxa_decrement_exception_refcount(void *primary_exception) throw();
+__cxa_decrement_exception_refcount(void *primary_exception) _LIBCXXABI_NOEXCEPT;
 
 // Apple extension to support std::uncaught_exception()
-extern _LIBCXXABI_FUNC_VIS bool __cxa_uncaught_exception() throw();
-extern _LIBCXXABI_FUNC_VIS unsigned int __cxa_uncaught_exceptions() throw();
+extern _LIBCXXABI_FUNC_VIS bool __cxa_uncaught_exception() _LIBCXXABI_NOEXCEPT;
+extern _LIBCXXABI_FUNC_VIS unsigned int __cxa_uncaught_exceptions() _LIBCXXABI_NOEXCEPT;
 
 #if defined(__linux__) || defined(__Fuchsia__)
 // Linux and Fuchsia TLS support. Not yet an official part of the Itanium ABI.
 // https://sourceware.org/glibc/wiki/Destructor%20support%20for%20thread_local%20variables
 extern _LIBCXXABI_FUNC_VIS int __cxa_thread_atexit(void (*)(void *), void *,
-                                                   void *) throw();
+                                                   void *) _LIBCXXABI_NOEXCEPT;
 #endif
 
 } // extern "C"