Use -O0 instead of -Og for Debug builds

[alexrp]

zig-sdk/src/sdk/ZigCompile.cs

Lines 238 to 250 in f3f8941

	// These exact flags are treated specially by zig cc/c++. They
	// activate Debug, ReleaseFast, ReleaseSafe, and ReleaseSmall
	// respectively. This in turns activates a bunch of other
	// mode-specific flags that we do not have to specify here as a
	// result.
	builder.AppendSwitch((_configuration, _releaseMode) switch
	{
	(ZigConfiguration.Debug, _) => "-Og",
	(ZigConfiguration.Release, ZigReleaseMode.Fast) => "-O3",
	(ZigConfiguration.Release, ZigReleaseMode.Safe) => "-O2 -fsanitize=undefined",
	(ZigConfiguration.Release, ZigReleaseMode.Small) => "-Oz",
	_ => throw new Exception(),
	});

See: ziglang/zig#11949

[alexrp]

Also review our use of -O3 vs -O2.