[FastISel][ARM] Fix a bug in the integer materialization code.

getRegClassFor returns the incorrect register class when in Thumb2 mode.
This fix simply manually selects the register class as in the code just a few
lines above.

There is no test case for this code, because the code is currently
unreachable. This will be changed in a future commit and existing test
cases will exercise this code.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215583 91177308-0d34-0410-b5e6-96231b3b80d8

Author: ributzka

lib/Target/ARM/ARMFastISel.cpp

@@ -536,7 +536,9 @@ unsigned ARMFastISel::ARMMaterializeInt(const Constant *C, MVT VT) {
       (ARM_AM::getSOImmVal(Imm) != -1);
     if (UseImm) {
       unsigned Opc = isThumb2 ? ARM::t2MVNi : ARM::MVNi;
-      unsigned ImmReg = createResultReg(TLI.getRegClassFor(MVT::i32));
+      const TargetRegisterClass *RC = isThumb2 ? &ARM::rGPRRegClass :
+                                                 &ARM::GPRRegClass;
+      unsigned ImmReg = createResultReg(RC);
       AddOptionalDefs(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
                               TII.get(Opc), ImmReg)
                       .addImm(Imm));