[CMake] Include the CMark exports in SwiftConfig.cmake

Since Swift's build tree configuration depends on CMark, we should also include the CMark targets if they are not present and the Exports file is available.

Author: Chris Bieneman

cmake/modules/SwiftConfig.cmake.in

@@ -17,6 +17,10 @@ set(SWIFT_LIBRARY_DIR "@SWIFT_CONFIG_LIBRARY_DIRS@")
 set(SWIFT_CMAKE_DIR "@SWIFT_CMAKE_DIR@")
 set(SWIFT_BINARY_DIR "@SWIFT_BINARY_DIR@")
 
+if(NOT TARGET libcmark_static AND ${product}_PATH_TO_CMARK_BUILD)
+  include(${${product}_PATH_TO_CMARK_BUILD}/src/CMarkExports.cmake)
+endif()
+
 if(NOT TARGET swift)
   set(SWIFT_EXPORTED_TARGETS "@SWIFT_CONFIG_EXPORTS@")
   include("@SWIFT_EXPORTS_FILE@")