[FIX] compiler: do not pass dynamic props object as is

The child receiving the props can observe changes made to the passed
t-props object which is not desirable.

src/compiler/code_generator.ts

@@ -1104,7 +1104,7 @@ export class CodeGenerator {
     let propString = propStr;
     if (ast.dynamicProps) {
       if (!props.length) {
-        propString = `${compileExpr(ast.dynamicProps)}`;
+        propString = `Object.assign({}, ${compileExpr(ast.dynamicProps)})`;
       } else {
         propString = `Object.assign({}, ${compileExpr(ast.dynamicProps)}, ${propStr})`;
       }