runtime: avoid the toolchain Swift registrar

Pass `-nostartfiles` to the driver as a staged toolchain would attempt
to link the Swift registrar which may not exist if the SDK is not
integrated. Furthermore, the registrar to be used is locally built and
not the one from the previous build.

Author: compnerd

Runtimes/Core/core/CMakeLists.txt

@@ -318,6 +318,8 @@ target_link_libraries(swiftCore
     swiftDemangling
     swiftStdlibStubs
     swiftThreading)
+target_link_options(swiftCore PRIVATE
+  -nostartfiles)
 if(NOT POLICY CMP0157)
   target_compile_options(swiftCore PRIVATE
     $<TARGET_OBJECTS:swiftRuntime>