ProfileData: Add support for the indexed instrprof format

This adds support for an indexed instrumentation based profiling
format, which is just a small header and an on disk hash table.  This
format will be used by clang's -fprofile-instr-use= for PGO.

llvm-svn: 206656
diff --git a/llvm/test/tools/llvm-profdata/errors.test b/llvm/test/tools/llvm-profdata/errors.test
index 6ccb084..50dd798 100644
--- a/llvm/test/tools/llvm-profdata/errors.test
+++ b/llvm/test/tools/llvm-profdata/errors.test
@@ -5,9 +5,9 @@
 OVERFLOW: overflow.profdata: overflow: Counter overflow
 
 RUN: not llvm-profdata show %p/Inputs/invalid-count-later.profdata 2>&1 | FileCheck %s --check-prefix=INVALID-COUNT-LATER
-RUN: not llvm-profdata merge %p/Inputs/invalid-count-later.profdata %p/Inputs/invalid-count-later.profdata 2>&1 | FileCheck %s --check-prefix=INVALID-COUNT-LATER
+RUN: not llvm-profdata merge %p/Inputs/invalid-count-later.profdata %p/Inputs/invalid-count-later.profdata -o /dev/null 2>&1 | FileCheck %s --check-prefix=INVALID-COUNT-LATER
 INVALID-COUNT-LATER: error: {{.*}}invalid-count-later.profdata: Malformed profile data
 
 RUN: not llvm-profdata show %p/Inputs/bad-hash.profdata 2>&1 | FileCheck %s --check-prefix=BAD-HASH
-RUN: not llvm-profdata merge %p/Inputs/bad-hash.profdata %p/Inputs/bad-hash.profdata 2>&1 | FileCheck %s --check-prefix=BAD-HASH
+RUN: not llvm-profdata merge %p/Inputs/bad-hash.profdata %p/Inputs/bad-hash.profdata -o /dev/null 2>&1 | FileCheck %s --check-prefix=BAD-HASH
 BAD-HASH: error: {{.*}}bad-hash.profdata: Malformed profile data