[compiler] Preserve JSX case semantics in constant propagation

[ousamabenyounes]

Summary

Fixes #35268.

ConstantPropagation's LoadLocal case rewrote $X = LoadLocal Comp into $X = LoadGlobal base whenever a component-named local aliased a lowercase global. When that lvalue was used as a simple JSX tag, codegen then emitted <base /> (treated as an intrinsic HTML element) instead of <Comp /> (a component reference), silently changing runtime behaviour.

Repro

const base = 'div';

function Component() {
  const Comp = base;
  return <Comp />;
}

Before this PR:

// compiled
t0 = <base />;   // rendered as the HTML `<base>` element

After this PR:

// compiled
t0 = <Comp />;   // rendered as <div /> via the Comp variable reference

Fix

constantPropagation now runs a pre-pass that collects the IdentifierId of every Place used as a simple JSX element tag (i.e. <X />, not <x.Y /> / <x:y />). In the LoadLocal rewrite step, the pass skips the substitution when:

1. the lvalue is one of those collected JSX-tag places, and
2. the resolved constant is a LoadGlobal, and
3. the local binding's name and the global binding's name have different JSX component-vs-intrinsic casing.

Primitive constant folding is unaffected. Member-expression JSX tags (e.g. <localVar.Stringify />) continue to propagate since the JSX-tag Place in that case is the PropertyLoad lvalue, not the LoadLocal lvalue. Same-casing rewrites (e.g. const MyLocal = Stringify; <MyLocal /> → <Stringify />, as exercised by jsx-local-tag-in-lambda.js) are also unaffected.

How did you test this change?

• yarn snap — 1720 passed / 1720 (1719 existing + 1 new regression fixture jsx-component-local-aliasing-lowercase-global).
• yarn workspace babel-plugin-react-compiler lint — clean.
• yarn flow dom-node — clean.
• yarn linc / yarn prettier — clean.
• Existing jsx-lowercase-localvar-memberexpr*, jsx-local-tag-in-lambda, jsx-tag-evaluation-order, const-propagation-into-function-expression-global fixtures continue to pass unchanged.

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