[CMake] Use global SWIFT_HOST_TRIPLE consistently

Instead of calling 'get_swift_host_triple()' repeatedly, because it
always return the same value.

Author: rintaro

cmake/modules/AddPureSwift.cmake

@@ -46,8 +46,7 @@ function(_add_host_swift_compile_options name)
     $<$<COMPILE_LANGUAGE:Swift>:-runtime-compatibility-version>
     $<$<COMPILE_LANGUAGE:Swift>:none>)
 
-  swift_get_host_triple(target)
-  target_compile_options(${name} PRIVATE $<$<COMPILE_LANGUAGE:Swift>:-target;${target}>)
+  target_compile_options(${name} PRIVATE $<$<COMPILE_LANGUAGE:Swift>:-target;${SWIFT_HOST_TRIPLE}>)
   _add_host_variant_swift_sanitizer_flags(${name})
 endfunction()
 

cmake/modules/AddSwift.cmake

@@ -131,22 +131,20 @@ endfunction()
 # Usage:
 # _add_host_variant_c_compile_link_flags(name)
 function(_add_host_variant_c_compile_link_flags name)
-  swift_get_host_triple(target)
-
   # MSVC and gcc don't understand -target.
   # clang-cl understands --target.
   if(CMAKE_C_COMPILER_ID MATCHES "Clang")
     if("${CMAKE_C_COMPILER_FRONTEND_VARIANT}" STREQUAL "MSVC") # clang-cl options
-      target_compile_options(${name} PRIVATE $<$<COMPILE_LANGUAGE:C,CXX,OBJC,OBJCXX>:--target=${target}>)
-      target_link_options(${name} PRIVATE $<$<COMPILE_LANGUAGE:C,CXX,OBJC,OBJCXX>:--target=${target}>)
+      target_compile_options(${name} PRIVATE $<$<COMPILE_LANGUAGE:C,CXX,OBJC,OBJCXX>:--target=${SWIFT_HOST_TRIPLE}>)
+      target_link_options(${name} PRIVATE $<$<COMPILE_LANGUAGE:C,CXX,OBJC,OBJCXX>:--target=${SWIFT_HOST_TRIPLE}>)
     else()
-      target_compile_options(${name} PRIVATE $<$<COMPILE_LANGUAGE:C,CXX,OBJC,OBJCXX>:-target;${target}>)
-      target_link_options(${name} PRIVATE $<$<COMPILE_LANGUAGE:C,CXX,OBJC,OBJCXX>:-target;${target}>)
+      target_compile_options(${name} PRIVATE $<$<COMPILE_LANGUAGE:C,CXX,OBJC,OBJCXX>:-target;${SWIFT_HOST_TRIPLE}>)
+      target_link_options(${name} PRIVATE $<$<COMPILE_LANGUAGE:C,CXX,OBJC,OBJCXX>:-target;${SWIFT_HOST_TRIPLE}>)
     endif()
   endif()
 
   if (CMAKE_Swift_COMPILER)
-    target_compile_options(${name} PRIVATE $<$<COMPILE_LANGUAGE:Swift>:-target;${target}>)
+    target_compile_options(${name} PRIVATE $<$<COMPILE_LANGUAGE:Swift>:-target;${SWIFT_HOST_TRIPLE}>)
 
    _add_host_variant_swift_sanitizer_flags(${name})
   endif()

test/CMakeLists.txt

@@ -210,8 +210,7 @@ normalize_boolean_spelling(SWIFT_STDLIB_ENABLE_OBJC_INTEROP)
 normalize_boolean_spelling(SWIFT_ENABLE_BACKTRACING)
 is_build_type_optimized("${SWIFT_STDLIB_BUILD_TYPE}" SWIFT_OPTIMIZED)
 
-# Get 'SWIFT_HOST_TRIPLE' and 'SWIFT_HOST_SDKROOT' for lit.site.cfg.in
-swift_get_host_triple(SWIFT_HOST_TRIPLE)
+# Get 'SWIFT_HOST_SDKROOT' for lit.site.cfg.in
 set(SWIFT_HOST_SDKROOT "${SWIFT_SDK_${SWIFT_HOST_VARIANT_SDK}_ARCH_${SWIFT_HOST_VARIANT_ARCH}_PATH}")
 
 set(profdata_merge_worker