Make the ABI changes only affect windows

TODO: decide upon rules for *nix systems

src/check_expr.c

@@ -1016,6 +1016,8 @@ Type *check_get_results(Checker *c, Scope *scope, AstNode *_results) {
 
 Type *type_to_abi_compat_param_type(gbAllocator a, Type *original_type) {
 	Type *new_type = original_type;
+
+	if (str_eq(build_context.ODIN_OS, str_lit("windows"))) {
 		// NOTE(bill): Changing the passing parameter value type is to match C's ABI
 		// IMPORTANT TODO(bill): This only matches the ABI on MSVC at the moment
 		// SEE: https://msdn.microsoft.com/en-us/library/zthk2dkh.aspx
@@ -1055,6 +1057,10 @@ Type *type_to_abi_compat_param_type(gbAllocator a, Type *original_type) {
 			}
 		} break;
 		}
+	} else {
+		// IMPORTANT TODO(bill): figure out the ABI settings for Linux, OSX etc. for
+		// their architectures
+	}
 
 	return new_type;
 }