Document that PR #62549 has already been ported

PR_62549_PORT_STATUS.md

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+# Port Status: microsoft/TypeScript#62549
+
+## Summary
+**Status: ✅ ALREADY PORTED**
+
+PR #62549 from microsoft/TypeScript has already been successfully ported to the Go codebase.
+
+## Details
+
+### Original Change
+The PR "Consistently resolve to the `errorType` on `arguments` with error" changed the TypeScript checker to pass `ignoreArrowFunctions: true` when checking if `arguments` is used in a property initializer or class static block.
+
+**TypeScript change (src/compiler/checker.ts):**
+```diff
+- if (isInPropertyInitializerOrClassStaticBlock(node)) {
++ if (isInPropertyInitializerOrClassStaticBlock(node, /*ignoreArrowFunctions*/ true)) {
+```
+
+### Go Implementation
+The equivalent change is already present in the Go codebase:
+
+**File:** `internal/checker/checker.go`, line 10599
+```go
+if c.isInPropertyInitializerOrClassStaticBlock(node, true /*ignoreArrowFunctions*/) {
+    c.error(node, diagnostics.X_arguments_cannot_be_referenced_in_property_initializers_or_class_static_initialization_blocks)
+    return c.errorType
+}
+```
+
+### Test Results
+- ✅ All tests pass
+- ✅ The specific test `argumentsUsedInClassFieldInitializerOrStaticInitializationBlock` passes
+- ✅ The testdata baseline shows the correct behavior (returning `any` type instead of `IArguments` for `arguments` in arrow functions within property initializers)
+
+### Baseline Differences
+The testdata contains `.diff` files showing differences between the Go implementation and the TypeScript submodule baselines. This is expected because:
+1. The Go implementation has the change
+2. The TypeScript submodule baselines haven't been regenerated yet (shallow clone)
+3. The test framework correctly handles these differences
+
+## History
+The change from PR #62549 was actually ported **before** it was merged into TypeScript!
+
+- **Oct 5, 2025**: @Andarist opened PR #1828 to port microsoft/TypeScript#48172 which added the `ignoreArrowFunctions` parameter
+- **In PR #1828**: The Go implementation was already passing `true` for `ignoreArrowFunctions` in the arguments check
+- **Oct 5, 2025**: @Andarist opened microsoft/TypeScript#62549 to make TypeScript match the Go behavior
+- **Oct 5, 2025**: PR #62549 was merged into TypeScript
+
+As noted in the [PR #1828 review](https://github.com/microsoft/typescript-go/pull/1828#discussion_r2404688959):
+> "this has some seemingly unwanted diffs but I think this is basically desired and I opened a PR to Strada to close this gap: microsoft/TypeScript#62549"
+
+## Conclusion
+No action needed. The change has been correctly ported and is functioning as expected. In fact, the Go port led the way, and TypeScript followed!