Support: improve identify_magic to recognize COFF bigobj

identify_magic recognized a COFF bigobj as an import library file.
This patch fixes that.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217627 91177308-0d34-0410-b5e6-96231b3b80d8
Remove the unused string section symbol parameter from DwarfFile::emitStrings

And since it /looked/ like the DwarfStrSectionSym was unused, I tried
removing it - but then it turned out that DwarfStringPool was
reconstructing the same label (and expecting it to have already been
emitted) and uses that.

So I kept it around, but wanted to pass it in to users - since it seemed
a bit silly for DwarfStringPool to have it passed in and returned but
itself have no use for it. The only two users don't handle strings in
both .dwo and .o files so they only ever need the one symbol - no need
to keep it (and have an unused symbol) in the DwarfStringPool used for
fission/.dwo.

Refactor a bunch of accelerator table usage to remove duplication so I
didn't have to touch 4-5 callers.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217628 91177308-0d34-0410-b5e6-96231b3b80d8
[CodeGenPrepare] Teach the addressing mode matcher how to promote zext.
I.e., teach it about 'sext (zext a to ty) to ty2' => zext a to ty2.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217629 91177308-0d34-0410-b5e6-96231b3b80d8
[C API] Make the 'lower switch' pass available via the C API.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217630 91177308-0d34-0410-b5e6-96231b3b80d8
Support: Delete {aligned_,}{u,}{little,big}8_t

The byte has no endianness, so these types don't make sense.
uint8_t should be used instead.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217631 91177308-0d34-0410-b5e6-96231b3b80d8