[cxx-interop] Build Cxx and CxxStdlib modules for macCatalyst

This enables building the C++ stdlib overlays (`Cxx.swiftmodule` and `CxxStdlib.swiftmodule`) for the Mac Catalyst target.

rdar://126938813

Author: egorzhdan

stdlib/public/Cxx/CMakeLists.txt

@@ -29,6 +29,7 @@ add_swift_target_library(swiftCxx STATIC NO_LINK_NAME IS_STDLIB IS_SWIFT_ONLY IS
 
     LINK_FLAGS "${SWIFT_RUNTIME_SWIFT_LINK_FLAGS}"
     DEPENDS ${SWIFT_CXX_DEPS}
+    MACCATALYST_BUILD_FLAVOR zippered
     INSTALL_IN_COMPONENT compiler
     INSTALL_WITH_SHARED)
 

stdlib/public/Cxx/std/CMakeLists.txt

@@ -58,6 +58,7 @@ add_swift_target_library(swiftCxxStdlib STATIC NO_LINK_NAME IS_STDLIB IS_SWIFT_O
 
     LINK_FLAGS "${SWIFT_RUNTIME_SWIFT_LINK_FLAGS}"
     TARGET_SDKS ALL_APPLE_PLATFORMS LINUX WINDOWS ANDROID
+    MACCATALYST_BUILD_FLAVOR zippered
     INSTALL_IN_COMPONENT compiler
     INSTALL_WITH_SHARED
     DEPENDS libstdcxx-modulemap libcxxshim_modulemap CxxStdlib-apinotes)