Use 'free' to release PerIDCache since it was allocated using calloc().

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@60556 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Lex/PTHLexer.cpp

@@ -244,7 +244,7 @@ PTHManager::PTHManager(const llvm::MemoryBuffer* buf, void* fileLookup,
 PTHManager::~PTHManager() {
   delete Buf;
   delete (PTHFileLookup*) FileLookup;
-  delete [] (IdentifierInfo**) PerIDCache;
+  assert(PerIDCache); free(PerIDCache);
 }
 
 PTHManager* PTHManager::Create(const std::string& file, Preprocessor& PP) {