Fix alignment.

test/test_suite/safe/deref_absolute.c3t

@@ -1,6 +1,18 @@
-module main;
+// #target: macos-x64
+module test;
 
-fn void main()
+fn int main()
 {
     int x = *(int*)1;
-}
+    return 0;
+}
+
+/* #expect: test.ll
+
+define i32 @main() #0 {
+entry:
+  %x = alloca i32, align 4
+  %0 = load i32, ptr inttoptr (i64 1 to ptr), align 1
+  store i32 %0, ptr %x, align 4
+  ret i32 0
+}