fix zig argument passing changes in str module

compiler/gen_llvm/src/llvm/build.rs

@@ -5337,7 +5337,17 @@ fn run_low_level<'a, 'ctx, 'env>(
 
             let string = load_symbol(scope, &args[0]);
 
-            call_bitcode_fn(env, &[string], intrinsic)
+            let result = call_bitcode_fn(env, &[string], intrinsic);
+
+            // zig passes the result as a packed integer sometimes, instead of a struct. So we cast
+            let expected_type = basic_type_from_layout(env, layout);
+            let actual_type = result.get_type();
+
+            if expected_type != actual_type {
+                complex_bitcast_check_size(env, result, expected_type, "str_to_num_cast")
+            } else {
+                result
+            }
         }
         StrFromInt => {
             // Str.fromInt : Int -> Str

compiler/gen_llvm/src/llvm/build_str.rs

@@ -155,16 +155,22 @@ pub fn str_from_utf8_range<'a, 'ctx, 'env>(
     let result_type = env.module.get_struct_type("str.FromUtf8Result").unwrap();
     let result_ptr = builder.build_alloca(result_type, "alloca_utf8_validate_bytes_result");
 
+    let count = env
+        .builder
+        .build_extract_value(count_and_start, 0, "get_count")
+        .unwrap();
+
+    let start = env
+        .builder
+        .build_extract_value(count_and_start, 1, "get_count")
+        .unwrap();
+
     call_void_bitcode_fn(
         env,
         &[
             list_symbol_to_c_abi(env, scope, list).into(),
-            complex_bitcast(
-                env.builder,
-                count_and_start.into(),
-                env.twice_ptr_int().into(),
-                "to_i128",
-            ),
+            count,
+            start,
             result_ptr.into(),
         ],
         bitcode::STR_FROM_UTF8_RANGE,