[llvm-ml] make TEXTEQU directive not to eagerly expand macros in arguments (#209526)
We observed a crash in `TEXTEQU` that pastes two macros into one.
```masm
.data
part1 TEXTEQU <1>
part2 TEXTEQU <0>
joined TEXTEQU part1, part2 ; crash
```
`part1` is immediately rewritten into `1` as integer, which is rejected
by `TEXTEQU` parser. We need to keep `part1` as identifier for `TEXTEQU`
to pick up later.