fs: deprecate never throw behaviour in fs.existsSync

Author: Ceres6

doc/api/deprecations.md

@@ -3786,6 +3786,19 @@ Type: Documentation-only
 Passing non-supported argument types is deprecated and, instead of returning `false`,
 will throw an error in a future version.
 
+### DEP0187: `fs.existsSync` never throw on invalid arguments
+
+<!-- YAML
+changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/55753
+    description: Runtime deprecation.
+-->
+
+Type: Runtime
+
+Returning false on validation errors is deprecated.
+
 [NIST SP 800-38D]: https://nvlpubs.nist.gov/nistpubs/Legacy/SP/nistspecialpublication800-38d.pdf
 [RFC 6066]: https://tools.ietf.org/html/rfc6066#section-3
 [RFC 8247 Section 2.4]: https://www.rfc-editor.org/rfc/rfc8247#section-2.4

lib/fs.js

@@ -151,6 +151,7 @@ const {
   validateString,
   kValidateObjectAllowNullable,
 } = require('internal/validators');
+const { deprecate } = require('internal/util');
 
 const permission = require('internal/process/permission');