Fix memory leak in globalisel.
Fix memory leak in globalisel.

    #0 0x89cdeb in operator new[](unsigned long) /code/llvm/projects/compiler-rt/lib/asan/asan_new_delete.cc:84:37
    #1 0x4ec87c4 in llvm::RegisterBankInfo::ValueMapping const* llvm::RegisterBankInfo::getOperandsMapping<llvm::RegisterBankInfo::ValueMapping const* const*>(llvm::RegisterBankInfo::ValueMapping const* const*, llvm::RegisterBankInfo::ValueMapping const* const*) const /code/llvm/lib/CodeGen/GlobalISel/RegisterBankInfo.cpp:297:9
    #2 0x9327ee in llvm::AArch64RegisterBankInfo::getInstrMapping(llvm::MachineInstr const&) const /code/llvm/lib/Target/AArch64/AArch64RegisterBankInfo.cpp:540:30
    #3 0x4eb8d07 in llvm::RegBankSelect::assignInstr(llvm::MachineInstr&) /code/llvm/lib/CodeGen/GlobalISel/RegBankSelect.cpp:546:24
    #4 0x4eb9dd2 in llvm::RegBankSelect::runOnMachineFunction(llvm::MachineFunction&) /code/llvm/lib/CodeGen/GlobalISel/RegBankSelect.cpp:624:12
    #5 0x3141875 in llvm::MachineFunctionPass::runOnFunction(llvm::Function&) /code/llvm/lib/CodeGen/MachineFunctionPass.cpp:62:13
    #6 0x396128d in llvm::FPPassManager::runOnFunction(llvm::Function&) /code/llvm/lib/IR/LegacyPassManager.cpp:1513:27
    #7 0x3961832 in llvm::FPPassManager::runOnModule(llvm::Module&) /code/llvm/lib/IR/LegacyPassManager.cpp:1534:16
    #8 0x3962540 in runOnModule /code/llvm/lib/IR/LegacyPassManager.cpp:1590:27
    #9 0x3962540 in llvm::legacy::PassManagerImpl::run(llvm::Module&) /code/llvm/lib/IR/LegacyPassManager.cpp:1693
    #10 0x8ae368 in compileModule(char**, llvm::LLVMContext&) /code/llvm/tools/llc/llc.cpp:562:8
    #11 0x8a7a1b in main /code/llvm/tools/llc/llc.cpp:316:22

git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@293351 91177308-0d34-0410-b5e6-96231b3b80d8

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