Fix a use-after-free bug found by ASan. You can't assign a temporary
std::string to a StringRef. Moreover, the method being called accepts
a Twine to simplify these patterns.

Fixes this ASan failure:
==6312== ERROR: AddressSanitizer: heap-use-after-free on address 0x7fd558b1af58 at pc 0xcb7529 bp 0x7fffff572080 sp 0x7fffff572078
READ of size 1 at 0x7fd558b1af58 thread T0
    #0 0xcb7528 .../llvm/include/llvm/ADT/StringRef.h:192 llvm::StringRef::operator[]()
    #1 0x1d53c0a .../llvm/include/llvm/ADT/StringExtras.h:128 llvm::HashString()
    #2 0x1d53878 .../llvm/lib/Support/StringMap.cpp:64 llvm::StringMapImpl::LookupBucketFor()
    #3 0x1b6872f .../llvm/include/llvm/ADT/StringMap.h:352 llvm::StringMap<>::GetOrCreateValue<>()
    #4 0x1b61836 .../llvm/lib/MC/MCContext.cpp:109 llvm::MCContext::GetOrCreateSymbol()
    #5 0xe9fd47 .../llvm/lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp:154 (anonymous namespace)::ARMELFStreamer::EmitMappingSymbol()
    #6 0xea01dd .../llvm/lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp:133 (anonymous namespace)::ARMELFStreamer::EmitDataMappingSymbol()
    #7 0xe9f78b .../llvm/lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp:91 (anonymous namespace)::ARMELFStreamer::EmitBytes()
    #8 0x1b15d82 .../llvm/lib/MC/MCStreamer.cpp:89 llvm::MCStreamer::EmitIntValue()
    #9 0xcc0f9b .../llvm/lib/Target/ARM/ARMAsmPrinter.cpp:713 llvm::ARMAsmPrinter::emitAttributes()
    #10 0xcc0d44 .../llvm/lib/Target/ARM/ARMAsmPrinter.cpp:632 llvm::ARMAsmPrinter::EmitStartOfAsmFile()
    #11 0x14692ad .../llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp:162 llvm::AsmPrinter::doInitialization()
    #12 0x1bc4677 .../llvm/lib/VMCore/PassManager.cpp:1561 llvm::FPPassManager::doInitialization()
    #13 0x1bc4990 .../llvm/lib/VMCore/PassManager.cpp:1595 llvm::MPPassManager::runOnModule()
    #14 0x1bc55e5 .../llvm/lib/VMCore/PassManager.cpp:1705 llvm::PassManagerImpl::run()
    #15 0x1bc5878 .../llvm/lib/VMCore/PassManager.cpp:1740 llvm::PassManager::run()
    #16 0xc3954d .../llvm/tools/llc/llc.cpp:378 compileModule()
    #17 0xc38001 .../llvm/tools/llc/llc.cpp:194 main
    #18 0x7fd557d6a11c __libc_start_main
0x7fd558b1af58 is located 24 bytes inside of 29-byte region [0x7fd558b1af40,0x7fd558b1af5d)
freed by thread T0 here:
    #0 0xc337da .../llvm/projects/compiler-rt/lib/asan/asan_new_delete.cc:56 operator delete()
    #1 0x1ee9cef .../libstdc++-v3/include/bits/basic_string.h:535 std::string::~string()
    #2 0xea01dd .../llvm/lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp:133 (anonymous namespace)::ARMELFStreamer::EmitDataMappingSymbol()
    #3 0xe9f78b .../llvm/lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp:91 (anonymous namespace)::ARMELFStreamer::EmitBytes()
    #4 0x1b15d82 .../llvm/lib/MC/MCStreamer.cpp:89 llvm::MCStreamer::EmitIntValue()
    #5 0xcc0f9b .../llvm/lib/Target/ARM/ARMAsmPrinter.cpp:713 llvm::ARMAsmPrinter::emitAttributes()
    #6 0xcc0d44 .../llvm/lib/Target/ARM/ARMAsmPrinter.cpp:632 llvm::ARMAsmPrinter::EmitStartOfAsmFile()
    #7 0x14692ad .../llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp:162 llvm::AsmPrinter::doInitialization()
    #8 0x1bc4677 .../llvm/lib/VMCore/PassManager.cpp:1561 llvm::FPPassManager::doInitialization()
    #9 0x1bc4990 .../llvm/lib/VMCore/PassManager.cpp:1595 llvm::MPPassManager::runOnModule()
    #10 0x1bc55e5 .../llvm/lib/VMCore/PassManager.cpp:1705 llvm::PassManagerImpl::run()
    #11 0x1bc5878 .../llvm/lib/VMCore/PassManager.cpp:1740 llvm::PassManager::run()
    #12 0xc3954d .../llvm/tools/llc/llc.cpp:378 compileModule()
    #13 0xc38001 .../llvm/tools/llc/llc.cpp:194 main
    #14 0x7fd557d6a11c __libc_start_main

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169668 91177308-0d34-0410-b5e6-96231b3b80d8
Fix an inadvertent typo error.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169671 91177308-0d34-0410-b5e6-96231b3b80d8
Fix Windows build breakage.

Windows does not have <stdint.h>, should include
"llvm/Support/DataTypes.h" instead.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169672 91177308-0d34-0410-b5e6-96231b3b80d8
Simplify code. Sort includes. No functionality change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169676 91177308-0d34-0410-b5e6-96231b3b80d8
Revert the patches adding a popcount loop idiom recognition pass.

There are still bugs in this pass, as well as other issues that are
being worked on, but the bugs are crashers that occur pretty easily in
the wild. Test cases have been sent to the original commit's review
thread.

This reverts the commits:
  r169671: Fix a logic error.
  r169604: Move the popcnt tests to an X86 subdirectory.
  r168931: Initial commit adding the pass.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169683 91177308-0d34-0410-b5e6-96231b3b80d8
Teach DAG combine to handle vector logical operations with vectors of all 1s or all 0s. These cases can show up when vectors are split for legalizing. Fix some tests that were dependent on these cases not being combined.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169684 91177308-0d34-0410-b5e6-96231b3b80d8