[FIX] compiler: t-model supports radio group in t-foreach

Have a radio group defined inside a t-foreach:
```xml
  <t t-foreach="values" t-as="val" t-key="val">
    <input name="radiogroup" t-att-value="val" t-model="state.radioGroup" />
  </t>
```

Before this commit the algorithm that set the "checked" attribute on the current active
radio button according to the state did not support having a dynamic value (`t-att-value`)

After this commit, this use case works as we go look in the dynamic attributes too.

src/compiler/code_generator.ts

@@ -632,7 +632,15 @@ export class CodeGenerator {
 
       let idx: number;
       if (specialInitTargetAttr) {
-        idx = block!.insertData(`${fullExpression} === '${attrs[targetAttr]}'`, "attr");
+        let targetExpr = targetAttr in attrs && `'${attrs[targetAttr]}'`;
+        if (!targetExpr && ast.attrs) {
+          // look at the dynamic attribute counterpart
+          const dynamicTgExpr = ast.attrs[`t-att-${targetAttr}`];
+          if (dynamicTgExpr) {
+            targetExpr = compileExpr(dynamicTgExpr);
+          }
+        }
+        idx = block!.insertData(`${fullExpression} === ${targetExpr}`, "attr");
         attrs[`block-attribute-${idx}`] = specialInitTargetAttr;
       } else if (hasDynamicChildren) {
         const bValueId = generateId("bValue");

tests/components/__snapshots__/t_model.test.ts.snap

@@ -569,6 +569,36 @@ exports[`t-model directive t-model with dynamic values on select options in fore
 }"
 `;
 
+exports[`t-model directive t-model with radio button group in t-foreach 1`] = `
+"function anonymous(app, bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, comment } = bdom;
+  let { prepareList, toNumber, withKey } = helpers;
+  
+  let block1 = createBlock(\`<div id=\\"get_data\\" block-handler-0=\\"click\\"><block-child-0/></div>\`);
+  let block3 = createBlock(\`<input type=\\"radio\\" name=\\"radio_group\\" block-attribute-0=\\"value\\" block-attribute-1=\\"id\\" block-attribute-2=\\"checked\\" block-handler-3=\\"click\\"/>\`);
+  
+  return function template(ctx, node, key = \\"\\") {
+    let hdlr1 = [ctx['getData'], ctx];
+    ctx = Object.create(ctx);
+    const [k_block2, v_block2, l_block2, c_block2] = prepareList(ctx['options']);;
+    for (let i1 = 0; i1 < l_block2; i1++) {
+      ctx[\`opt\`] = v_block2[i1];
+      const key1 = ctx['opt'];
+      let attr1 = new String((ctx['opt']) || \\"\\");
+      let attr2 = ctx['opt'];
+      const bExpr1 = ctx['state'];
+      const expr1 = 'group';
+      let attr3 = bExpr1[expr1] === ctx['opt'];
+      let hdlr2 = [(ev) => { bExpr1[expr1] = ev.target.value; }];
+      c_block2[i1] = withKey(block3([attr1, attr2, attr3, hdlr2]), key1);
+    }
+    const b2 = list(c_block2);
+    return block1([hdlr1], [b2]);
+  }
+}"
+`;
+
 exports[`t-model directive two inputs in a div alternating with a t-if 1`] = `
 "function anonymous(app, bdom, helpers
 ) {

tests/components/t_model.test.ts

@@ -644,4 +644,35 @@ describe("t-model directive", () => {
     const input = fixture.querySelector("input")!;
     await editInput(input, "Beam me up, Scotty");
   });
+
+  test("t-model with radio button group in t-foreach", async () => {
+    expect.assertions(6);
+    const steps: string[] = [];
+    class SomeComponent extends Component {
+      static template = xml`
+        <div t-on-click="getData" id="get_data">
+          <t t-foreach="options" t-as="opt" t-key="opt">
+            <input type="radio" name="radio_group" t-model="state.group" t-att-value="opt" t-att-id="opt"/>
+          </t>
+        </div>
+      `;
+      state = useState({ group: "scotty" });
+      options = ["beam", "scotty"];
+
+      getData() {
+        steps.push(`group: ${this.state.group}`);
+      }
+    }
+    await mount(SomeComponent, fixture);
+    const divEl = fixture.querySelector("#get_data") as HTMLElement;
+    expect(fixture.querySelector("input:checked")!.getAttribute("id")).toBe("scotty");
+    divEl.click();
+    expect(steps).toEqual(["group: scotty"]);
+    fixture.querySelector("input")!.click();
+    expect(steps).toEqual(["group: scotty", "group: beam"]);
+    await nextTick();
+    expect(fixture.querySelector("input:checked")!.getAttribute("id")).toBe("beam");
+    divEl.click();
+    expect(steps).toEqual(["group: scotty", "group: beam", "group: beam"]);
+  });
 });