Ensure parity between C/C++ and Zig projects with regards to unwind tables

[alexrp]

Zig doesn't emit the .eh_frame and .eh_frame_hdr sections by default. However, C/C++ compilers (including zig cc/zig c++) do. We should align the behavior as much as possible by default.

[alexrp]

See: ziglang/zig#9067

[alexrp]

Looks like the upstream situation has improved considerably:

• Add DWARF unwinding, and an external debug info loader for ELF ziglang/zig#15823
• Unwinding follow up: Don't strip compiler_rt symbols, enable unwind tables on supported platforms ziglang/zig#16559

Zig now just does the sensible thing by default, which is to include unwind tables on any target where they're supported and useful for providing backtraces. This goes for Zig code and C/C++ code.

[alexrp]

I don't think we actually need to do anything here after all. We could consider a property to disable unwind tables for size optimization purposes, but that's a separate feature request.