* testsuite/libjava.jni/jni.exp (gcj_jni_compile_c_to_so): Use
	additional option "-Wmissing-prototypes" for compiling C sources.
	Print actual filename for pass/fail rather than $name.c.
	* testsuite/libjava.jni/PR15133.java: New testcase file.
	* testsuite/libjava.jni/PR15133.c: Likewise.
	* testsuite/libjava.jni/PR15133.out: Likewise.

Co-Authored-By: Tom Tromey <tromey@redhat.com>

From-SVN: r81358