Add a simple way to test the X64 emitter. Update native.

unittest/TestX64Emitter.cpp

@@ -0,0 +1,43 @@
+#include "Common/X64Emitter.h"
+#include "Core/MIPS/x86/RegCacheFPU.h"
+#include "Core/MIPS/x86/Jit.h"
+#include "Core/MIPS/JitCommon/JitState.h"
+#include "Core/MIPS/JitCommon/JitCommon.h"
+#include "Core/MIPS/MIPSVFPUUtils.h"
+#include "ext/disarm.h"
+
+#include "UnitTest.h"
+
+static const u8 *prevStart = NULL;
+
+bool CheckLast(Gen::XEmitter &emit, const char *comp) {
+	auto vec = DisassembleX86(prevStart, emit.GetCodePtr() - prevStart);
+	EXPECT_EQ_STR(vec[0], std::string(comp));
+	return true;
+}
+
+void PrintLast(Gen::XEmitter &emit) {
+	for (const u8 *p = prevStart; p < emit.GetCodePtr(); p++) {
+		printf("%02x ", *p);
+	}
+	printf("\n");
+}
+
+bool TestX64Emitter() {
+	using namespace Gen;
+
+	u32 code[512];
+	XEmitter emitter((u8 *)code);
+
+	prevStart = emitter.GetCodePtr();
+	emitter.VADDSD(XMM0, XMM1, R(XMM7));
+	RET(CheckLast(emitter, "vaddsd xmm0, xmm1, xmm7"));
+
+	prevStart = emitter.GetCodePtr();
+	emitter.VMULSD(XMM0, XMM1, R(XMM7));
+	RET(CheckLast(emitter, "vmulsd xmm0, xmm1, xmm7"));
+
+	// Just for checking.
+	PrintLast(emitter);
+	return true;
+}