Explore Implications of `+thumb-mode` linker flag.

[Tropix126]

Problem Description

The +thumb-mode linker flag shaves off roughly 12kb of binary size from build artifacts, which is pretty nice. I'm not completely sure if there are significant tradeoffs in this area though (we already enable +thumb2 instructions), so we should probably run some benchmarks with/without it.

Screenshots

"Hello World" binary size from pros-rs 0.7:

Additional information

N/A