Previously ADD & ADDA (as well as SUB & SUBA) instructions are mixed
together, which not only violated Motorola assembly's syntax but also
made asm parsing more difficult. This patch separates these two kinds of
instructions migrate rest of the tests from
test/CodeGen/M68k/Encoding/Arithmetic to test/MC/M68k/Arithmetic.
Note that we observed minor regressions on codegen quality: Sometimes
isel uses ADD instead of ADDA even the latter can lead to shorter
sequence of code. This issue implies that some isel patterns might need
to be updated.
This patch adds supports for inline assembly operands and some simple
operand constraints, including register and constant operands.
Differential Revision: https://reviews.llvm.org/D102585