Invalidate liveness in ARMConstantIslandPass.

This pass splits basic blocks to insert constant islands, and it
doesn't recompute the live-in lists. No later passes depend on accurate
liveness information.

This fixes PR12410 where the machine code verifier was complaining.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@153700 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Target/ARM/ARMConstantIslandPass.cpp

@@ -21,6 +21,7 @@
 #include "llvm/CodeGen/MachineConstantPool.h"
 #include "llvm/CodeGen/MachineFunctionPass.h"
 #include "llvm/CodeGen/MachineJumpTableInfo.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
 #include "llvm/Target/TargetData.h"
 #include "llvm/Target/TargetMachine.h"
 #include "llvm/Support/Debug.h"
@@ -392,6 +393,9 @@ bool ARMConstantIslands::runOnMachineFunction(MachineFunction &mf) {
 
   HasFarJump = false;
 
+  // This pass invalidates liveness information when it splits basic blocks.
+  MF->getRegInfo().invalidateLiveness();
+
   // Renumber all of the machine basic blocks in the function, guaranteeing that
   // the numbers agree with the position of the block in the function.
   MF->RenumberBlocks();