[libFuzzer] trace switch statements and apply mutations based on the expected case values

llvm-svn: 243726
diff --git a/llvm/lib/Fuzzer/test/fuzzer.test b/llvm/lib/Fuzzer/test/fuzzer.test
index d6dd3ff..63cb957 100644
--- a/llvm/lib/Fuzzer/test/fuzzer.test
+++ b/llvm/lib/Fuzzer/test/fuzzer.test
@@ -31,3 +31,6 @@
 
 RUN: not LLVMFuzzer-StrncmpTest -use_traces=1 -seed=1 -runs=10000    2>&1 | FileCheck %s
 RUN:     LLVMFuzzer-StrncmpTest               -seed=1 -runs=1000000  2>&1 | FileCheck %s --check-prefix=Done1000000
+
+RUN: not LLVMFuzzer-SwitchTest -use_traces=1 -seed=1 -runs=100000    2>&1 | FileCheck %s
+RUN:     LLVMFuzzer-SwitchTest               -seed=1 -runs=1000000  2>&1 | FileCheck %s --check-prefix=Done1000000