[LibCallShrinkWrap] Added ilogb in performCallErrors()

ilogb libcall was not being constant folded correctly.
It was due to LibCallShrinkWrap pass not handling
ilogbx, as a result SimplifyCFG pass did not remove
redundant libcall. This patch adds ilogb case in
performCallErrors().

Fixes #101873

Author: kshitijvp

llvm/lib/Transforms/Utils/LibCallsShrinkWrap.cpp

@@ -246,6 +246,7 @@ bool LibCallsShrinkWrap::performCallErrors(CallInst *CI,
   case LibFunc_logb:   // Same as log
   case LibFunc_logbf:  // Same as log
   case LibFunc_logbl:  // Same as log
+  case LibFunc_ilogb:  // Same as log
   {
     ++NumWrappedOneCond;
     Cond = createCond(CI, CmpInst::FCMP_OLE, 0.0f);