Shader: Initial implementation of x86_x64 JIT compiler for Pica vertex shaders.

- Config: Add an option for selecting to use shader JIT or interpreter.
- Qt: Add a menu option for enabling/disabling the shader JIT.

src/video_core/shader/shader_jit.cpp

@@ -0,0 +1,36 @@
+// Copyright 2015 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include "video_core/pica.h"
+
+#include "shader.h"
+#include "shader_jit.h"
+
+namespace Pica {
+
+namespace Shader {
+
+JitShader::JitShader() : jitted(nullptr) {
+}
+
+void JitShader::DoJit(JitCompiler& jit) {
+    jitted = jit.Compile();
+}
+
+void JitShader::Run(UnitState& state) {
+    if (jitted)
+        jitted(&state);
+}
+
+JitCompiler::JitCompiler() {
+    AllocCodeSpace(1024 * 1024 * 4);
+}
+
+void JitCompiler::Clear() {
+    ClearCodeSpace();
+}
+
+} // namespace Shader
+
+} // namespace Pica