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