Moved the run_foo_test functions to a separate file

Author: Nicholas-Baron

Diff for: src/tools/compiletest/src/runtest.rs

@@ -18,6 +18,7 @@ use std::str;
 use tracing::*;
 
 mod test_cx;
+mod test_cx_run_test_fns;
 use test_cx::TestCx;
 
 #[cfg(test)]