[CMake] Fatal error when bootstrapping is not "hosttools"
and Swift parser integration is enabled.
If swift parser integration is enabled, SwiftSyntax libraries are always
built with host tools. Other SwiftCompilerSources modules must use the
same runtime with parser libraries.
(cherry picked from commit 0f0c4925ae2a70c635f4ad881991d937658b5b63)
(cherry picked from commit bf0081ad564eb65ab94aafa19640b2c4ffdf6938)
