[LTT] Directly create inbounds gep (NFCI)

We know that this gep is inbounds. Constant expression construction
already infers this fact, but make it explicit.

Author: nikic

llvm/lib/Transforms/IPO/LowerTypeTests.cpp

@@ -879,7 +879,7 @@ void LowerTypeTestsModule::buildBitSetsFromGlobalVariables(
     // Multiply by 2 to account for padding elements.
     Constant *CombinedGlobalIdxs[] = {ConstantInt::get(Int32Ty, 0),
                                       ConstantInt::get(Int32Ty, I * 2)};
-    Constant *CombinedGlobalElemPtr = ConstantExpr::getGetElementPtr(
+    Constant *CombinedGlobalElemPtr = ConstantExpr::getInBoundsGetElementPtr(
         NewInit->getType(), CombinedGlobal, CombinedGlobalIdxs);
     assert(GV->getType()->getAddressSpace() == 0);
     GlobalAlias *GAlias =