common: Move assert failure handling into a cpp file.

Advantage: Altering the handler does not need a full recompilation.
Disadvantage: noreturn is droped, so the caller is a bit slower.

We quite often run yuzu with a YOLO assertion handler. In fact, only very few
games run at all with asserts. This patch allows developers to patch the handler
without recompiling everything. The overhead of the missing "noreturn" attribute
shoul be negletable.

src/common/CMakeLists.txt

@@ -97,6 +97,7 @@ add_custom_command(OUTPUT scm_rev.cpp
 add_library(common STATIC
     algorithm.h
     alignment.h
+    assert.cpp
     assert.h
     atomic_ops.h
     detached_tasks.cpp

src/common/assert.cpp

@@ -0,0 +1,11 @@
+// Copyright 2021 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include "common/assert.h"
+
+#include "common/common_funcs.h"
+
+void assert_handle_failure() {
+    Crash();
+}

src/common/assert.h

@@ -4,10 +4,13 @@
 
 #pragma once
 
-#include <cstdlib>
-#include "common/common_funcs.h"
 #include "common/logging/log.h"
 
+// Sometimes we want to try to continue even after hitting an assert.
+// However touching this file yields a global recompilation as this header is included almost
+// everywhere. So let's just move the handling of the failed assert to a single cpp file.
+void assert_handle_failure();
+
 // For asserts we'd like to keep all the junk executed when an assert happens away from the
 // important code in the function. One way of doing this is to put all the relevant code inside a
 // lambda and force the compiler to not inline it. Unfortunately, MSVC seems to have no syntax to
@@ -17,15 +20,14 @@
 // enough for our purposes.
 template <typename Fn>
 #if defined(_MSC_VER)
-[[msvc::noinline, noreturn]]
+[[msvc::noinline]]
 #elif defined(__GNUC__)
-[[gnu::cold, gnu::noinline, noreturn]]
+[[gnu::cold, gnu::noinline]]
 #endif
 static void
 assert_noinline_call(const Fn& fn) {
     fn();
-    Crash();
+    assert_handle_failure();
-    exit(1); // Keeps GCC's mouth shut about this actually returning
 }
 
 #define ASSERT(_a_)                                                                                \