rts/RtsFlags: Refactor size parsing
This makes a number of improvements mentioned in #20201 (closed):
- fail if the argument cannot be parsed as a number (
-Mturtles
) - fail if an unrecognized unit is given (e.g.
-M1x
)
This makes a number of improvements mentioned in #20201 (closed):
-Mturtles
)-M1x
)