Memory, size and exit errors with dynamic library rendering

[CrazyboyQCD]

Seperate from #5152
Commits in ascending order:
After #4849 (4623863 related with upstream winit, hard to find out the root cause same thing like #5152 (comment) but only different in error code)
The exit error:

error: process didn't exit successfully: `target\debug\e_test.exe` (exit code: 0xc0000005, STATUS_ACCESS_VIOLATION)

After #4305 (65b0676)
The running error:

Called `available_rect()` before `Context::run()`

stacktrace.txt

After #5056 (97eaf83)
The running error:

unsafe precondition(s) violated: ptr::copy_nonoverlapping requires that both pointer arguments are aligned and non-null and the specified memory ranges do not overlap

stacktrace.txt

After #4744 (0faab82)
The running error:

unsafe precondition(s) violated: slice::from_raw_parts requires the pointer to be aligned and non-null, and the total size of the slice not to exceed `isize::MAX`

stacktrace.txt

[CrazyboyQCD]

Above issues except first one are disappeared in 0.29.1.

[0thElement]

Hello, the second issue still persist even in 0.29.1.

I encountered this after trying to get hot-lib-reloader-rs working with the latest egui version. After updating the dependency of eframe in the example examples/hot-egui from 0.19.0 to 0.29.1, the issue appeared.