[runtime] Don't install libswiftRuntime.a

libswiftRuntime.a is an internal object file. Its contents are incorporated
into libswiftCore.dylib and libswiftCore.a.

rdar://25353757

Author: Greg Parker

stdlib/public/runtime/CMakeLists.txt

@@ -68,7 +68,7 @@ add_swift_library(swiftRuntime IS_STDLIB IS_STDLIB_CORE
   ${swift_runtime_leaks_sources}
   ${swift_runtime_port_sources}
   C_COMPILE_FLAGS ${swift_runtime_compile_flags}
-  INSTALL_IN_COMPONENT stdlib)
+  INSTALL_IN_COMPONENT never_install)
 
 if(CMAKE_SYSTEM_NAME STREQUAL "Linux" OR CMAKE_SYSTEM_NAME STREQUAL "FreeBSD")
   add_swift_library(section_magic_begin IS_STDLIB IS_STDLIB_CORE