Revert "CMake: Runtimes: Specify language mode explicitly."

Reverting since we can use `CMAKE_Swift_LANGUAGE_VERSION` instead.

This reverts commit 6cc9a7d.

Author: etcwilde

Runtimes/Core/CMakeLists.txt

@@ -181,7 +181,6 @@ add_link_options($<$<PLATFORM_ID:Linux>:LINKER:-z,defs>)
 add_compile_options(
   $<$<COMPILE_LANGUAGE:Swift>:-explicit-module-build>
   "$<$<COMPILE_LANGUAGE:Swift>:-nostdlibimport>"
-  "$<$<COMPILE_LANGUAGE:Swift>:SHELL:-swift-version 5>"
   "$<$<COMPILE_LANGUAGE:Swift>:SHELL:-library-level api>"
   "$<$<COMPILE_LANGUAGE:Swift>:SHELL:-runtime-compatibility-version none>"
   "$<$<COMPILE_LANGUAGE:Swift>:-disable-autolinking-runtime-compatibility-dynamic-replacements>"

Runtimes/Overlay/Cxx/CMakeLists.txt

@@ -31,7 +31,6 @@ target_compile_options(swiftCxx PRIVATE
   # This module should not pull in the C++ standard library, so we disable it
   # explicitly.  For functionality that depends on the C++ stdlib, use C++
   # stdlib overlay (`swiftstd` module).
-  "$<$<COMPILE_LANGUAGE:Swift>:SHELL:-swift-version 5>"
   "$<$<COMPILE_LANGUAGE:Swift>:SHELL:-Xcc -nostdinc++>"
   "$<$<COMPILE_LANGUAGE:Swift>:SHELL:-enable-experimental-feature AllowUnsafeAttribute>"
   "$<$<COMPILE_LANGUAGE:Swift>:SHELL:-enable-experimental-feature BuiltinModule>"

Runtimes/Supplemental/Differentiation/CMakeLists.txt

@@ -66,7 +66,6 @@ add_compile_options(
   $<$<COMPILE_LANGUAGE:Swift>:-explicit-module-build>
   $<$<COMPILE_LANGUAGE:Swift>:-nostdlibimport>
   $<$<COMPILE_LANGUAGE:Swift>:-parse-stdlib>
-  "$<$<COMPILE_LANGUAGE:Swift>:SHELL:-swift-version 5>"
   "$<$<COMPILE_LANGUAGE:Swift>:SHELL:-library-level api>"
   "$<$<COMPILE_LANGUAGE:Swift>:SHELL:-enable-experimental-feature NoncopyableGenerics2>"
   "$<$<COMPILE_LANGUAGE:Swift>:SHELL:-enable-experimental-feature SuppressedAssociatedTypes>"

Runtimes/Supplemental/Distributed/CMakeLists.txt

@@ -69,7 +69,6 @@ add_compile_options(
   $<$<COMPILE_LANGUAGE:Swift>:-explicit-module-build>
   $<$<COMPILE_LANGUAGE:Swift>:-nostdlibimport>
   $<$<COMPILE_LANGUAGE:Swift>:-strict-memory-safety>
-  "$<$<COMPILE_LANGUAGE:Swift>:SHELL:-swift-version 5>"
   "$<$<COMPILE_LANGUAGE:Swift>:SHELL:-enable-experimental-feature NoncopyableGenerics2>"
   "$<$<COMPILE_LANGUAGE:Swift>:SHELL:-enable-experimental-feature SuppressedAssociatedTypes>"
   "$<$<COMPILE_LANGUAGE:Swift>:SHELL:-enable-experimental-feature SE427NoInferenceOnExtension>"

Runtimes/Supplemental/Observation/CMakeLists.txt

@@ -64,7 +64,6 @@ option(${PROJECT_NAME}_ENABLE_PRESPECIALIZATION "Enable generic metadata prespec
 add_compile_options(
   $<$<COMPILE_LANGUAGE:Swift>:-explicit-module-build>
   $<$<COMPILE_LANGUAGE:Swift>:-nostdlibimport>
-  "$<$<COMPILE_LANGUAGE:Swift>:SHELL:-swift-version 5>"
   "$<$<COMPILE_LANGUAGE:Swift>:SHELL:-Xfrontend -enforce-exclusivity=unchecked>"
   "$<$<COMPILE_LANGUAGE:Swift>:SHELL:-Xfrontend -target-min-inlining-version -Xfrontend min>"
   "$<$<COMPILE_LANGUAGE:Swift>:SHELL:-Xfrontend -disable-implicit-string-processing-module-import>"

Runtimes/Supplemental/StringProcessing/CMakeLists.txt

@@ -53,7 +53,6 @@ option(${PROJECT_NAME}_ENABLE_PRESPECIALIZATION "Enable generic metadata prespec
 add_compile_options(
   $<$<COMPILE_LANGUAGE:Swift>:-explicit-module-build>
   $<$<COMPILE_LANGUAGE:Swift>:-nostdlibimport>
-  "$<$<COMPILE_LANGUAGE:Swift>:SHELL:-swift-version 5>"
   "$<$<COMPILE_LANGUAGE:Swift>:SHELL:-Xfrontend -disable-implicit-concurrency-module-import>"
   "$<$<COMPILE_LANGUAGE:Swift>:SHELL:-Xfrontend -disable-implicit-string-processing-module-import>"
   "$<$<COMPILE_LANGUAGE:Swift>:-warn-implicit-overrides>"

Runtimes/Supplemental/Synchronization/CMakeLists.txt

@@ -72,7 +72,6 @@ add_compile_options(
   $<$<COMPILE_LANGUAGE:Swift>:-nostdlibimport>
   $<$<COMPILE_LANGUAGE:Swift>:-enable-builtin-module>
   $<$<COMPILE_LANGUAGE:Swift>:-strict-memory-safety>
-  "$<$<COMPILE_LANGUAGE:Swift>:SHELL:-swift-version 5>"
   "$<$<COMPILE_LANGUAGE:Swift>:SHELL:-enable-experimental-feature NoncopyableGenerics2>"
   "$<$<COMPILE_LANGUAGE:Swift>:SHELL:-enable-experimental-feature SuppressedAssociatedTypes>"
   "$<$<COMPILE_LANGUAGE:Swift>:SHELL:-enable-experimental-feature SE427NoInferenceOnExtension>"

Runtimes/Supplemental/Volatile/CMakeLists.txt

@@ -67,7 +67,6 @@ add_compile_options(
   $<$<COMPILE_LANGUAGE:Swift>:-explicit-module-build>
   $<$<COMPILE_LANGUAGE:Swift>:-nostdlibimport>
   $<$<COMPILE_LANGUAGE:Swift>:-strict-memory-safety>
-  "$<$<COMPILE_LANGUAGE:Swift>:SHELL:-swift-version 5>"
   "$<$<AND:$<BOOL:${${PROJECT_NAME}_ENABLE_LIBRARY_EVOLUTION}>,$<COMPILE_LANGUAGE:Swift>>:-enable-library-evolution>"
   "$<$<AND:$<BOOL:${${PROJECT_NAME}_ENABLE_PRESPECIALIZATION}>,$<COMPILE_LANGUAGE:Swift>>:SHELL:-Xfrontend -prespecialize-generic-metadata>")