[valueblocks] ternary tests showing assignment bug

A ternary that reassigns the same variable in both branches causes some 
weirdness with LeaveSSA, this PR just adds the failing case.

compiler/forget/src/__tests__/fixtures/hir/ternary-assignment-expression.expect.md

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+
+## Input
+
+```javascript
+
+```
+
+## Code
+
+```javascript
+
+```
+      

compiler/forget/src/__tests__/fixtures/hir/ternary-assignment-expression.js

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+// @only
+function ternary(props) {
+  let x = 0;
+  const y = props.a ? (x = 1) : (x = 2);
+  return x + y;
+}

compiler/forget/src/__tests__/fixtures/hir/ternary-expression.expect.md

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+
+## Input
+
+```javascript
+function ternary(props) {
+  const a = props.a && props.b ? props.c || props.d : props.e ?? props.f;
+  const b = props.a ? (props.b && props.c ? props.d : props.e) : props.f;
+  return a ? b : null;
+}
+
+```
+
+## Code
+
+```javascript
+function ternary(props) {
+  const $ = React.useMemoCache();
+  const c_0 = $[0] !== props;
+  let t1;
+  if (c_0) {
+    t1 = props.a && props.b ? props.c || props.d : props.e ?? props.f;
+    $[0] = props;
+    $[1] = t1;
+  } else {
+    t1 = $[1];
+  }
+  const a = t1;
+  const c_2 = $[2] !== props;
+  let t3;
+  if (c_2) {
+    t3 = props.a ? (props.b && props.c ? props.d : props.e) : props.f;
+    $[2] = props;
+    $[3] = t3;
+  } else {
+    t3 = $[3];
+  }
+  const b = t3;
+  const c_4 = $[4] !== a;
+  const c_5 = $[5] !== b;
+  let t6;
+  if (c_4 || c_5) {
+    t6 = a ? b : null;
+    $[4] = a;
+    $[5] = b;
+    $[6] = t6;
+  } else {
+    t6 = $[6];
+  }
+  return t6;
+}
+
+```
+      

compiler/forget/src/__tests__/fixtures/hir/ternary-expression.js

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+function ternary(props) {
+  const a = props.a && props.b ? props.c || props.d : props.e ?? props.f;
+  const b = props.a ? (props.b && props.c ? props.d : props.e) : props.f;
+  return a ? b : null;
+}