util: Force emission of stack frame in stack unit test
The `capture_not_overwritten` unit test captures and compares two backtraces -- one from inside a call to `func_c` and one outside -- and confirms that they are not identical. That is, that `func_c` is in the backtrace. On 32-bit x86, without `-fno-omit-frame-pointer`, the function will not emit a stack frame. As a result, the unit test fails. The fix is to compile `func_c` with the flag `-fno-omit-frame-pointer` to prevent the compiler from optimizing out the stack frame which is otherwise unneeded. Bug: https://bugs.gentoo.org/823774 Closes: mesa/mesa#4091 Fixes: d0d14f3f ("util: Add unit test for stack backtrace caputure") Part-of: <mesa/mesa!30622> (cherry picked from commit 05dc4eb5)