CMake: Re-use external xbyak target if present (#62)

CMakeLists.txt

@@ -96,9 +96,6 @@ include_directories(${Boost_INCLUDE_DIRS})
 include_directories(externals/catch)
 enable_testing(true)  # Enables unit-testing.
 
-# Include Xbyak
-include_directories(externals/xbyak/xbyak)
-
 # Include LLVM
 if (DYNARMIC_USE_LLVM)
     find_package(LLVM REQUIRED CONFIG)

externals/CMakeLists.txt

@@ -6,3 +6,10 @@ if (NOT DYNARMIC_NO_BUNDLED_FMT)
     # fmtlib formatting library
     add_subdirectory(fmt)
 endif()
+
+if (NOT TARGET xbyak)
+    if (ARCHITECTURE_x86 OR ARCHITECTURE_x86_64)
+        add_library(xbyak INTERFACE)
+        target_include_directories(xbyak INTERFACE ${CMAKE_CURRENT_SOURCE_DIR}/xbyak/xbyak)
+    endif()
+endif()

src/CMakeLists.txt

@@ -107,3 +107,4 @@ target_link_libraries(dynarmic PRIVATE fmt-header-only)
 if (CMAKE_SYSTEM_NAME STREQUAL "Windows")
     target_compile_definitions(dynarmic PRIVATE FMT_USE_WINDOWS_H=0)
 endif()
+target_link_libraries(dynarmic PRIVATE xbyak)