build: separate out host build of SwiftRemoteMirror

Separate out the host build of SwiftRemoteMirror from the "target" build
(the host for the standard library may be different from the host for
the compiler).  Restructure the build to ensure that we use the correct
compiler for building the SwiftRemoteMirror for the host.  This fixes a
build issue when building for Linux AArch64.

Author: compnerd

lib/CMakeLists.txt

@@ -38,6 +38,7 @@ add_subdirectory(Sema)
 add_subdirectory(Serialization)
 add_subdirectory(SwiftDemangle)
 add_subdirectory(SwiftReflection)
+add_subdirectory(SwiftRemoteMirror)
 add_subdirectory(SIL)
 add_subdirectory(SILGen)
 add_subdirectory(SILOptimizer)

lib/SwiftRemoteMirror/CMakeLists.txt

@@ -0,0 +1,5 @@
+add_swift_host_library(swiftRemoteMirror STATIC
+  ${SWIFT_SOURCE_DIR}/stdlib/public/SwiftRemoteMirror/SwiftRemoteMirror.cpp)
+if(CMAKE_SYSTEM_NAME STREQUAL Windows)
+  target_compile_definitions(swiftRemoteMirror PRIVATE _LIB)
+endif()

stdlib/public/SwiftRemoteMirror/CMakeLists.txt

@@ -14,31 +14,3 @@ if(SWIFT_BUILD_DYNAMIC_STDLIB)
                            INSTALL_IN_COMPONENT
                              swift-remote-mirror)
 endif()
-
-# Build a specific version for the host with the host toolchain.  This is going
-# to be used by tools (e.g. lldb)
-if(SWIFT_INCLUDE_TOOLS)
-  if(NOT SWIFT_BUILD_DYNAMIC_STDLIB)
-    add_custom_target(swiftRemoteMirror-${SWIFT_SDK_${SWIFT_HOST_VARIANT_SDK}_LIB_SUBDIR})
-  endif()
-
-  if(NOT SWIFT_BUILD_RUNTIME_WITH_HOST_COMPILER)
-    set(CURRENT_CMAKE_C_COMPILER ${CMAKE_C_COMPILER})
-    set(CURRENT_CMAKE_CXX_COMPILER ${CMAKE_CXX_COMPILER})
-    set(CMAKE_C_COMPILER ${HOST_CMAKE_C_COMPILER})
-    set(CMAKE_CXX_COMPILER ${HOST_CMAKE_CXX_COMPILER})
-  endif()
-
-  add_swift_host_library(swiftRemoteMirror STATIC
-    SwiftRemoteMirror.cpp)
-  target_compile_definitions(swiftRemoteMirror PRIVATE _LIB)
-  target_compile_options(swiftRemoteMirror PRIVATE
-    ${SWIFT_RUNTIME_CXX_FLAGS})
-  set_property(TARGET swiftRemoteMirror APPEND_STRING PROPERTY LINK_FLAGS
-    ${SWIFT_RUNTIME_LINK_FLAGS})
-
-  if(NOT SWIFT_BUILD_RUNTIME_WITH_HOST_COMPILER)
-    set(CMAKE_C_COMPILER ${CURRENT_CMAKE_C_COMPILER})
-    set(CMAKE_CXX_COMPILER ${CURRENT_CMAKE_CXX_COMPILER})
-  endif()
-endif()