`make test` outputs `TEST SUCCESS` after unsuccessful exit of JVM. One example is bad VM flags.

I now have a reproducer for something that has puzzled me before (and most of my co-workers I think):

// first test uses -XX:+UseG1GC second and third uses -XX:+UseG1GCC (sic)
`make clean run-test TEST=open/test/hotspot/jtreg/gc/arguments/TestCompressedClassFlags.java JTREG='JAVA_OPTIONS=-XX:+UseG1GC'` -> OK
`make run-test TEST=open/test/hotspot/jtreg/gc/arguments/TestCompressedClassFlags.java JTREG='JAVA_OPTIONS=-XX:+UseG1GCC'` -> OK
`rm -rf test-results/jtreg_open_test_hotspot_jtreg_gc_arguments_TestCompressedClassFlags_java`
`make run-test TEST=open/test/hotspot/jtreg/gc/arguments/TestCompressedClassFlags.java JTREG='JAVA_OPTIONS=-XX:+UseG1GCC'` -> FAIL

The problem is that the success of the first test run seems to be cached and the second test-run seems to reuse the result of the first run.

This seems to fix the problem:
```
diff --git a/make/RunTests.gmk b/make/RunTests.gmk
index 25dcdbb083d..489c3f839f8 100644
--- a/make/RunTests.gmk
+++ b/make/RunTests.gmk
@@ -864,6 +864,7 @@ define SetupRunJtregTestBody

   clean-workdir-$1:
        $$(RM) -r $$($1_TEST_SUPPORT_DIR)
+ $$(RM) -r $$($1_TEST_RESULTS_DIR)

   $1_COMMAND_LINE := \
       $$(JAVA) $$($1_JTREG_LAUNCHER_OPTIONS) \
```