Merge pull request #19263 from jrose-apple/install-installer-installest

[CMake] Install swiftinterface files alongside swiftmodules

Author: jrose-apple

cmake/modules/SwiftSource.cmake

@@ -333,12 +333,9 @@ function(_compile_swift_files
     endif()
   endif()
 
-  # If we want to build a single overlay, don't install the swiftmodule and swiftdoc files.
-  if(NOT BUILD_STANDALONE)
-    swift_install_in_component("${SWIFTFILE_INSTALL_IN_COMPONENT}"
-        FILES "${module_file}" "${module_doc_file}"
-        DESTINATION "lib${LLVM_LIBDIR_SUFFIX}/swift/${library_subdir}")
-  endif()
+  swift_install_in_component("${SWIFTFILE_INSTALL_IN_COMPONENT}"
+    FILES "${module_file}" "${module_doc_file}" "${interface_file}"
+    DESTINATION "lib${LLVM_LIBDIR_SUFFIX}/swift/${library_subdir}")
 
   set(line_directive_tool "${SWIFT_SOURCE_DIR}/utils/line-directive")
   set(swift_compiler_tool "${SWIFT_NATIVE_SWIFT_TOOLS_PATH}/swiftc")