cctools/ld64: Add ARM64 support

cctools/ld64/src/CMakeLists.txt

@@ -1,5 +1,9 @@
 project(ld64)
 
+if(CMAKE_HOST_SYSTEM_PROCESSOR MATCHES "aarch64")
+    add_compile_definitions(__arm64__)
+endif()
+
 add_definitions(-DHAVE_BCMP=1 -DHAVE_BZERO=1 -DHAVE_BCOPY=1 -DHAVE_INDEX=1 -DHAVE_RINDEX=1)
 
 set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fblocks -std=c++11 -Wno-long-long -Wno-import -Wno-format -Wno-deprecated -Wno-unused-variable -Wno-unused-private-field -Wno-unused-function -Wno-invalid-offsetof -Wno-int-conversion -Wno-char-subscripts -Wno-shift-negative-value")
@@ -15,8 +19,6 @@ include_directories(${CMAKE_CURRENT_SOURCE_DIR}/abstraction)
 include_directories(${CMAKE_CURRENT_SOURCE_DIR})
 
 add_definitions(-U__APPLE__
-	-DEMULATED_HOST_CPU_TYPE=16777223
-	-DEMULATED_HOST_CPU_SUBTYPE=3
 	-D__STDC_LIMIT_MACROS=1
 	-D__STDC_CONSTANT_MACROS=1
 	-DHAVE_EXECINFO_H=1
@@ -25,6 +27,19 @@ add_definitions(-U__APPLE__
 	-DSTDC_HEADERS=1 -DHAVE_SYS_TYPES_H=1 -DHAVE_SYS_STAT_H=1 -DHAVE_STDLIB_H=1 -DHAVE_STRING_H=1 -DHAVE_MEMORY_H=1 -DHAVE_STRINGS_H=1 -DHAVE_INTTYPES_H=1 -DHAVE_STDINT_H=1 -DHAVE_UNISTD_H=1 -DHAVE_DLFCN_H=1
 	-Du_short=uint16_t)
 
+# i386 has a different CPU type/subtype, but Darling only supports x86_64
+if (TARGET_x86_64 OR TARGET_i386)
+	add_definitions(
+		-DEMULATED_HOST_CPU_TYPE=16777223
+		-DEMULATED_HOST_CPU_SUBTYPE=3
+	)
+elseif (TARGET_ARM64)
+	add_definitions(
+		-DEMULATED_HOST_CPU_TYPE=16777228
+		-DEMULATED_HOST_CPU_SUBTYPE=0
+	)
+endif(TARGET_x86_64 OR TARGET_i386)
+
 set(ld64_sources
 	./ld/InputFiles.cpp
 	./ld/OutputFile.cpp