add IsText parameter to open yaml file (#9899)

Author: abhina-sree

llvm/lib/Transforms/IPO/LowerTypeTests.cpp

@@ -1876,8 +1876,8 @@ bool LowerTypeTestsModule::runForTesting(Module &M, ModuleAnalysisManager &AM) {
   if (!ClReadSummary.empty()) {
     ExitOnError ExitOnErr("-lowertypetests-read-summary: " + ClReadSummary +
                           ": ");
-    auto ReadSummaryFile =
-        ExitOnErr(errorOrToExpected(MemoryBuffer::getFile(ClReadSummary)));
+    auto ReadSummaryFile = ExitOnErr(errorOrToExpected(
+        MemoryBuffer::getFile(ClReadSummary, /*IsText=*/true)));
 
     yaml::Input In(ReadSummaryFile->getBuffer());
     In >> Summary;