[Threading] Fix compatibility library deployment target issue.

The threading library is being pulled into the compatibility libraries,
but in order to do that we need to make sure it gets built with the
correct deployment target.  (Which means we need a special version for
the compatibility libraries.)

rdar://96709941

Author: al45tair

stdlib/public/Threading/CMakeLists.txt

@@ -11,11 +11,18 @@ add_swift_target_library(swiftThreading OBJECT_LIBRARY
   "${SWIFT_SOURCE_DIR}/lib/Threading/Win32.cpp"
   INSTALL_IN_COMPONENT never_install)
 
-# This is only used by the compatibility libraries
-add_swift_target_library(swiftThreadingWithFatal OBJECT_LIBRARY
-  "${SWIFT_SOURCE_DIR}/lib/Threading/C11.cpp"
-  "${SWIFT_SOURCE_DIR}/lib/Threading/Linux.cpp"
-  "${SWIFT_SOURCE_DIR}/lib/Threading/Pthreads.cpp"
-  "${SWIFT_SOURCE_DIR}/lib/Threading/Win32.cpp"
-  "${SWIFT_SOURCE_DIR}/lib/Threading/Errors.cpp"
-  INSTALL_IN_COMPONENT never_install)
+if(SWIFT_STDLIB_SUPPORT_BACK_DEPLOYMENT)
+  # This is only used by the compatibility libraries
+  add_swift_target_library(swiftCompatibilityThreading OBJECT_LIBRARY
+    "${SWIFT_SOURCE_DIR}/lib/Threading/C11.cpp"
+    "${SWIFT_SOURCE_DIR}/lib/Threading/Linux.cpp"
+    "${SWIFT_SOURCE_DIR}/lib/Threading/Pthreads.cpp"
+    "${SWIFT_SOURCE_DIR}/lib/Threading/Win32.cpp"
+    INSTALL_IN_COMPONENT never_install
+    TARGET_SDKS ${SWIFT_DARWIN_PLATFORMS}
+    DEPLOYMENT_VERSION_OSX ${COMPATIBILITY_MINIMUM_DEPLOYMENT_VERSION_OSX}
+    DEPLOYMENT_VERSION_IOS ${COMPATIBILITY_MINIMUM_DEPLOYMENT_VERSION_IOS}
+    DEPLOYMENT_VERSION_TVOS ${COMPATIBILITY_MINIMUM_DEPLOYMENT_VERSION_TVOS}
+    DEPLOYMENT_VERSION_WATCHOS ${COMPATIBILITY_MINIMUM_DEPLOYMENT_VERSION_WATCHOS}
+  )
+endif()

stdlib/toolchain/Compatibility50/CMakeLists.txt

@@ -8,7 +8,7 @@ add_swift_target_library("${library_name}" STATIC
 
   C_COMPILE_FLAGS ${CXX_COMPILE_FLAGS}
   LINK_FLAGS ${CXX_LINK_FLAGS}
-  INCORPORATE_OBJECT_LIBRARIES swiftThreading
+  INCORPORATE_OBJECT_LIBRARIES swiftCompatibilityThreading
   SWIFT_COMPILE_FLAGS ${SWIFT_STANDARD_LIBRARY_SWIFT_FLAGS}
   DEPLOYMENT_VERSION_OSX ${COMPATIBILITY_MINIMUM_DEPLOYMENT_VERSION_OSX}
   DEPLOYMENT_VERSION_IOS ${COMPATIBILITY_MINIMUM_DEPLOYMENT_VERSION_IOS}

stdlib/toolchain/Compatibility51/CMakeLists.txt

@@ -9,7 +9,7 @@ add_swift_target_library("${library_name}" STATIC
 
   C_COMPILE_FLAGS ${CXX_COMPILE_FLAGS}
   LINK_FLAGS ${CXX_LINK_FLAGS}
-  INCORPORATE_OBJECT_LIBRARIES swiftThreading
+  INCORPORATE_OBJECT_LIBRARIES swiftCompatibilityThreading
   SWIFT_COMPILE_FLAGS ${SWIFT_STANDARD_LIBRARY_SWIFT_FLAGS}
   DEPLOYMENT_VERSION_OSX ${COMPATIBILITY_MINIMUM_DEPLOYMENT_VERSION_OSX}
   DEPLOYMENT_VERSION_IOS ${COMPATIBILITY_MINIMUM_DEPLOYMENT_VERSION_IOS}

stdlib/toolchain/CompatibilityConcurrency/CMakeLists.txt

@@ -7,7 +7,7 @@ add_swift_target_library("${library_name}" STATIC
 
   C_COMPILE_FLAGS ${CXX_COMPILE_FLAGS}
   LINK_FLAGS ${CXX_LINK_FLAGS}
-  INCORPORATE_OBJECT_LIBRARIES swiftThreading
+  INCORPORATE_OBJECT_LIBRARIES swiftCompatibilityThreading
   SWIFT_COMPILE_FLAGS ${SWIFT_STANDARD_LIBRARY_SWIFT_FLAGS}
   DEPLOYMENT_VERSION_OSX ${COMPATIBILITY_MINIMUM_DEPLOYMENT_VERSION_OSX}
   DEPLOYMENT_VERSION_IOS ${COMPATIBILITY_MINIMUM_DEPLOYMENT_VERSION_IOS}

stdlib/toolchain/CompatibilityDynamicReplacements/CMakeLists.txt

@@ -7,7 +7,7 @@ add_swift_target_library("${library_name}" STATIC
 
   C_COMPILE_FLAGS ${CXX_COMPILE_FLAGS}
   LINK_FLAGS ${CXX_LINK_FLAGS}
-  INCORPORATE_OBJECT_LIBRARIES swiftThreading
+  INCORPORATE_OBJECT_LIBRARIES swiftCompatibilityThreading
   SWIFT_COMPILE_FLAGS ${SWIFT_STANDARD_LIBRARY_SWIFT_FLAGS}
   DEPLOYMENT_VERSION_OSX ${COMPATIBILITY_MINIMUM_DEPLOYMENT_VERSION_OSX}
   DEPLOYMENT_VERSION_IOS ${COMPATIBILITY_MINIMUM_DEPLOYMENT_VERSION_IOS}