[LibFuzzer] test_single_input option to run a single test case.

-test_single_input flag specifies a file name with test data.

Review URL: http://reviews.llvm.org/D13359

Patch by Mike Aizatsky!

llvm-svn: 249096
diff --git a/llvm/lib/Fuzzer/test/fuzzer.test b/llvm/lib/Fuzzer/test/fuzzer.test
index 70dbce8..29bd807 100644
--- a/llvm/lib/Fuzzer/test/fuzzer.test
+++ b/llvm/lib/Fuzzer/test/fuzzer.test
@@ -1,6 +1,7 @@
 CHECK: BINGO
 
 RUN: LLVMFuzzer-SimpleTest 2>&1 | FileCheck %s
+RUN: LLVMFuzzer-SimpleTest -test_single_input=%S/hi.txt 2>&1 | FileCheck %s 
 
 RUN: not LLVMFuzzer-InfiniteTest -timeout=2 2>&1 | FileCheck %s --check-prefix=InfiniteTest
 InfiniteTest: ALARM: working on the last Unit for