[*] basic in-house cpp linting (#4039)

- add `#pragma once` to remainder files
- "correcter" defines (ANDROID), see https://groups.google.com/g/android-ndk/c/cf9_f1SLXls
- extra miscelly fixups

Signed-off-by: lizzie <lizzie@eden-emu.dev>

Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/4039
Reviewed-by: MaranBr <maranbr@eden-emu.dev>
Reviewed-by: crueter <crueter@eden-emu.dev>

src/shader_recompiler/backend/spirv/emit_spirv_convert.cpp

@@ -151,7 +151,7 @@ Id EmitConvertU32U64(EmitContext& ctx, Id value) {
 }
 
 Id EmitConvertF16F32(EmitContext& ctx, Id value) {
-#ifdef ANDROID
+#ifdef __ANDROID__
     return ctx.OpFConvert(ctx.F16[1], value);
 #else
     const auto result = ctx.OpFConvert(ctx.F16[1], value);