Revert "Fix PR18361: Invalidate LoopDispositions after LoopSimplify hoists things."

This commit was the source of crasher PR18384:

While deleting: label %for.cond127
An asserting value handle still pointed to this value!
UNREACHABLE executed at llvm/lib/IR/Value.cpp:671!

Reverting to get the builders green, feel free to re-land after fixing up.
(Renato has a handy isolated repro if you need it.)

This reverts commit r198478.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198503 91177308-0d34-0410-b5e6-96231b3b80d8
Tag x86 move to/from debug/control registers with Not64BitMode/In64BitMode. Remove disassembler hack.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198515 91177308-0d34-0410-b5e6-96231b3b80d8
Add missed cleanup from r198456

All other uses of this macro in LLVM/clang have been moved to the function
definition so follow suite (and the usage advice) here too for consistency.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198516 91177308-0d34-0410-b5e6-96231b3b80d8
Add a FIXME.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198528 91177308-0d34-0410-b5e6-96231b3b80d8
Don't use PrintFatalError(which calls exit) for 'Primary decode conflict'. Just skip emitting the table. This way the main function will delete the output file instead of it remaining empty and confusing dependency checks if build is invoked a second time.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198529 91177308-0d34-0410-b5e6-96231b3b80d8
Mark the 64-bit x86 push/pop instructions as In64BitMode. Mark the corresponding 32-bit versions with the same encodings Not64BitMode. Remove hack from tablegen disassembler table emitter. Fix bad test.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198530 91177308-0d34-0410-b5e6-96231b3b80d8
Emit an error message if the value passed to __builtin_returnaddress isn't a constant

__builtin_returnaddress requires that the value passed into is be a constant.
However, at -O0 even a constant expression may not be converted to a constant.
Emit an error message intead of crashing.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198531 91177308-0d34-0410-b5e6-96231b3b80d8
Simplify the PatternMatch unittest by giving it a module, function, and
basic block to hold instructions, and managing all of their lifetimes in
a fixture. This makes it easy to sink the expectations into the test
cases themselves which also makes things a bit more explicit and clearer
IMO.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198532 91177308-0d34-0410-b5e6-96231b3b80d8
[Sparc] Add initial implementation of MC Code emitter for sparc.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198533 91177308-0d34-0410-b5e6-96231b3b80d8
Use a shorter name for the IRBuilder member. This will help the tests
I'm adding next be a lot more readable.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198534 91177308-0d34-0410-b5e6-96231b3b80d8
Add lit.local.cfg for MC/Sparc


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198536 91177308-0d34-0410-b5e6-96231b3b80d8
Attempt to fix buildbots by XFAILing some architectures.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198537 91177308-0d34-0410-b5e6-96231b3b80d8
Fix a bug in IRBuilder that's been there for who knows how long. It
failed to correctly propagate the NUW and NSW flags to the constant
folder for two instructions. I've added a unittest to cover flag
propagation for the rest of the instructions and constant expressions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198538 91177308-0d34-0410-b5e6-96231b3b80d8
Add support to the pattern match library for matching NSW and NUW
instructions. I needed this for a quick experiment I was making, and
while I've no idea if that will ever get committed, I didn't want to
throw away the pattern match code and for anyone else to have to write
it again. I've added unittests to make sure this works correctly.

In fun news, this also uncovered the IRBuilder bug. Doh!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198541 91177308-0d34-0410-b5e6-96231b3b80d8
Add a new x86 specific instruction flag to force some isCodeGenOnly instructions to go through to the disassembler tables without resorting to string matches. Apply flag to all _REV instructions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198543 91177308-0d34-0410-b5e6-96231b3b80d8
Use new ForceDisassemble flag on the 2-byte forms of INC/DEC for 32-bit mode and remove disassmbler table emitter hack.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198544 91177308-0d34-0410-b5e6-96231b3b80d8
Mark x86 _alt instructions as AsmParserOnly so they will be omitted from disassembler without string matches.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198545 91177308-0d34-0410-b5e6-96231b3b80d8
Remove no longer needed x86 disassembler hack.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198546 91177308-0d34-0410-b5e6-96231b3b80d8
Fix encoding for PUSH64i16. Add In64BitMode Predicate. Remove disassembler hack.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198547 91177308-0d34-0410-b5e6-96231b3b80d8
Use patterns to remove some duplicate instructions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198550 91177308-0d34-0410-b5e6-96231b3b80d8