Rollup merge of #99227 - Lokathor:fix-thumbv4t-none-eabi-frame-pointer, r=davidtwco

Rollup merge of #99227 - Lokathor:fix-thumbv4t-none-eabi-frame-pointer, r=davidtwco

Fix thumbv4t-none-eabi frame pointer setting

The `thumb_base` profile has changed since I last remember seeing it, and now it sets the frame pointer to "always keep", which is not desired for this target. Hooking a debugger to the running program is not really done, it's preferable to have the register available for actual program use, so the default "may omit" is now set.

I thought that the target was already using "may omit" when I checked on it last month, because I forgot that the target was previously based on `thumb_base` rather than `Default::default()`. I only noticed the issue just now when creating the `armv4t-none-eabi` target (https://github.com/rust-lang/rust/pull/99226), though this PR is not in any way conditional on that one.