Undo unrelated change.

Author: snehasish

llvm/lib/Transforms/Instrumentation/MemProfiler.cpp

@@ -95,7 +95,7 @@ static cl::opt<bool> ClInsertVersionCheck(
 // This flag may need to be replaced with -f[no-]memprof-reads.
 static cl::opt<bool> ClInstrumentReads("memprof-instrument-reads",
                                        cl::desc("instrument read instructions"),
-                                       cl::Hidden, cl::init(false));
+                                       cl::Hidden, cl::init(true));
 
 static cl::opt<bool>
     ClInstrumentWrites("memprof-instrument-writes",