Move test to local compiler test directory

Moved erasableSyntaxOnlyJS test from the TypeScript submodule to the
local test directory at testdata/tests/cases/compiler/. This is the
correct location for new test cases specific to tsgo.

Co-authored-by: jakebailey <[email protected]>

Author: Copilot

testdata/baselines/reference/submodule/compiler/erasableSyntaxOnlyJS.errors.txt renamed to testdata/baselines/reference/compiler/erasableSyntaxOnlyJS.errors.txt

@@ -0,0 +1,22 @@
+// @erasableSyntaxOnly: true
+// @allowJs: true
+// @checkJs: true
+// @noEmit: true
+
+// JavaScript files should not have erasableSyntaxOnly checks
+// because they are already "erased" by definition.
+
+// @Filename: bar.cjs
+module.exports = {
+    a: 1,
+}
+
+// @Filename: foo.js
+module.exports = {
+    b: 2,
+}
+
+// @Filename: index.ts
+// These should still error because they are in a TypeScript file
+import bar = require("./bar.cjs");
+import foo = require("./foo.js");