[msan] Switch to -msan-handle-icmp-exact my default (#113200)

Fixes #111212.

This grows .text by 5.3% on CTMark, (or 2.6% large internal binary)
Perf regressed by 1.6%. We will try to improve in follow up patches.

It worth to pay some performance regression to fix
correctness to avoid stuff like #111212.

Author: vitalybuka

llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp

@@ -276,7 +276,7 @@ static cl::opt<bool>
 static cl::opt<bool>
     ClHandleICmpExact("msan-handle-icmp-exact",
                       cl::desc("exact handling of relational integer ICmp"),
-                      cl::Hidden, cl::init(false));
+                      cl::Hidden, cl::init(true));
 
 static cl::opt<bool> ClHandleLifetimeIntrinsics(
     "msan-handle-lifetime-intrinsics",