Make Ninja happy

Ninja requires that all output files be explicitly listed, and Ninja complained
that it didn't know how to build bin/goto-gcc. (BYPRODUCTS is only used by
Ninja.)

Author: tautschnig

src/goto-cc/CMakeLists.txt

@@ -32,5 +32,6 @@ else()
   add_custom_command(TARGET goto-cc
     POST_BUILD
     COMMAND "${CMAKE_COMMAND}" -E create_symlink
-      goto-cc $<TARGET_FILE_DIR:goto-cc>/goto-gcc)
+      goto-cc $<TARGET_FILE_DIR:goto-cc>/goto-gcc
+    BYPRODUCTS ${CMAKE_BINARY_DIR}/bin/goto-gcc)
 endif()