Enable the Swift diagnostic formatter for standard library builds

Author: DougGregor

stdlib/public/CMakeLists.txt

@@ -36,6 +36,9 @@ elseif(CMAKE_SYSTEM_NAME STREQUAL "OpenBSD")
   list(APPEND SWIFT_RUNTIME_CORE_CXX_FLAGS "-xc++")
 endif()
 
+# Use the new diagnostic formatter.
+list(APPEND SWIFT_RUNTIME_SWIFT_COMPILE_FLAGS "-diagnostic-style" "swift")
+
 # We should avoid non-literals in format strings, or appropriately mark
 # functions.
 check_cxx_compiler_flag("-Wformat-nonliteral -Werror=format-nonliteral" CXX_SUPPORTS_FORMAT_NONLITERAL_WARNING)

stdlib/public/Concurrency/CMakeLists.txt

@@ -148,6 +148,7 @@ add_swift_target_library(swift_Concurrency ${SWIFT_STDLIB_LIBRARY_BUILD_TYPES} I
     ${SWIFT_STANDARD_LIBRARY_SWIFT_FLAGS}
     -parse-stdlib
     -Xfrontend -enable-experimental-concurrency
+    -diagnostic-style swift
     ${SWIFT_RUNTIME_CONCURRENCY_SWIFT_FLAGS}
   ${swift_concurrency_options}
   INSTALL_IN_COMPONENT ${swift_concurrency_install_component}