Add IsText parameter to open yaml file (#116992)

Add IsText parameter to open yaml file
this fixes `FAIL: LLVM :: Transforms/LowerTypeTests/cfi-icall-alias.ll`

Co-authored-by: Abhina Sreeskantharajan <Abhina.Sreeskantharajan@ibm.com>
diff --git a/llvm/lib/Transforms/IPO/LowerTypeTests.cpp b/llvm/lib/Transforms/IPO/LowerTypeTests.cpp
index bfcf491..87d2432 100644
--- a/llvm/lib/Transforms/IPO/LowerTypeTests.cpp
+++ b/llvm/lib/Transforms/IPO/LowerTypeTests.cpp
@@ -1876,8 +1876,8 @@
   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;