[fuzzer] Add support for token-based fuzzing (e.g. for C++). Allow string flags. 

llvm-svn: 233745
diff --git a/llvm/lib/Fuzzer/test/fuzzer.test b/llvm/lib/Fuzzer/test/fuzzer.test
index 19fafe3..2a0e95f 100644
--- a/llvm/lib/Fuzzer/test/fuzzer.test
+++ b/llvm/lib/Fuzzer/test/fuzzer.test
@@ -23,3 +23,6 @@
 
 RUN: not ./LLVMFuzzer-DFSanSimpleCmpTest -seed=1 -timeout=15 2>&1 | FileCheck %s --check-prefix=DFSanSimpleCmpTest
 DFSanSimpleCmpTest: Found the target:
+
+RUN: not ./LLVMFuzzer-CxxTokensTest -seed=1 -timeout=15 -tokens=%S/../cxx_fuzzer_tokens.txt 2>&1 | FileCheck %s --check-prefix=CxxTokensTest
+CxxTokensTest: Found the target, exiting