refactor: use execFileSync in find-unused-diagnostic-messages script

Replaces execSync (shell string interpolation) with execFileSync (argument
array) to avoid shell expansion entirely. diagName is derived from
repo-controlled diagnostic identifiers so there is no practical injection
risk, but the array form is the more idiomatic and robust Node.js pattern
for invoking subprocesses.

Also restores original CRLF line endings to avoid unrelated line-ending
noise in the diff.

Co-Authored-By: Claude Sonnet 4.6 <[email protected]>

Author: orbisai0security

scripts/find-unused-diganostic-messages.mjs

@@ -1,31 +1,31 @@
-// This file requires a modern version of node 14+, and grep to be available.
-
-// node scripts/find-unused-diagnostic-messages.mjs
-import { execFileSync } from "child_process";
-import { readFileSync } from "fs";
-import { EOL } from "os";
-
-const diags = readFileSync("src/compiler/diagnosticInformationMap.generated.ts", "utf8");
-const startOfDiags = diags.split("export const Diagnostics")[1];
-
-/** @type {string[]} */
-const missingNames = [];
-startOfDiags.split(EOL).forEach(line => {
-    if (!line.includes(":")) return;
-    const diagName = line.split(":")[0].trim();
-
-    try {
-        execFileSync("grep", ["-rnw", "src", "-e", `Diagnostics.${diagName}`]);
-        process.stdout.write(".");
-    }
-    catch {
-        missingNames.push(diagName);
-        process.stdout.write("x");
-    }
-});
-
-if (missingNames.length) {
-    process.exitCode = 1;
-    console.log("Could not find usage of these diagnostics in the codebase:");
-    console.log(missingNames);
-}
+// This file requires a modern version of node 14+, and grep to be available.
+
+// node scripts/find-unused-diagnostic-messages.mjs
+import { execFileSync } from "child_process";
+import { readFileSync } from "fs";
+import { EOL } from "os";
+
+const diags = readFileSync("src/compiler/diagnosticInformationMap.generated.ts", "utf8");
+const startOfDiags = diags.split("export const Diagnostics")[1];
+
+/** @type {string[]} */
+const missingNames = [];
+startOfDiags.split(EOL).forEach(line => {
+    if (!line.includes(":")) return;
+    const diagName = line.split(":")[0].trim();
+
+    try {
+        execFileSync("grep", ["-rnw", "src", "-e", `Diagnostics.${diagName}`]);
+        process.stdout.write(".");
+    }
+    catch {
+        missingNames.push(diagName);
+        process.stdout.write("x");
+    }
+});
+
+if (missingNames.length) {
+    process.exitCode = 1;
+    console.log("Could not find usage of these diagnostics in the codebase:");
+    console.log(missingNames);
+}