Use JS library dependency system for warnOnce. NFC (#24702)

Both `warnOnce` and these string functions are now part of the JS
library and so they can use the normal JS dependency system.

Author: sbc100

src/lib/libstrings.js

@@ -39,7 +39,12 @@ addToLibrary({
    * @param {boolean=} ignoreNul - If true, the function will not stop on a NUL character.
    * @return {string}
    */`,
-  $UTF8ArrayToString__deps: ['$UTF8Decoder', '$findStringEnd'],
+  $UTF8ArrayToString__deps: [
+    '$UTF8Decoder', '$findStringEnd',
+#if ASSERTIONS
+    '$warnOnce',
+#endif
+  ],
   $UTF8ArrayToString: (heapOrArray, idx = 0, maxBytesToRead, ignoreNul) => {
 #if CAN_ADDRESS_2GB
     idx >>>= 0;
@@ -142,6 +147,9 @@ addToLibrary({
    *                                   terminator.
    * @return {number} The number of bytes written, EXCLUDING the null terminator.
    */
+#if ASSERTIONS
+  $stringToUTF8Array__deps: ['$warnOnce'],
+#endif
   $stringToUTF8Array: (str, heap, outIdx, maxBytesToWrite) => {
 #if CAN_ADDRESS_2GB
     outIdx >>>= 0;

test/other/test_unoptimized_code_size.js.size

@@ -1 +1 @@
-53970
+53973

test/other/test_unoptimized_code_size_strict.js.size

@@ -1 +1 @@
-52020
+52023

tools/link.py

@@ -1512,15 +1512,6 @@ def limit_incoming_module_api():
     settings.MINIFY_WASM_IMPORTS_AND_EXPORTS = 1
     settings.MINIFY_WASM_IMPORTED_MODULES = 1
 
-  if settings.MINIMAL_RUNTIME and settings.ASSERTIONS:
-    # In ASSERTIONS-builds, functions UTF8ArrayToString() and stringToUTF8Array()
-    # (which are not JS library functions), both use warnOnce(), which in
-    # MINIMAL_RUNTIME is a JS library function, so explicitly have to mark
-    # dependency to warnOnce() in that case. If string functions are turned to
-    # library functions in the future, then JS dependency tracking can be
-    # used and this special directive can be dropped.
-    settings.DEFAULT_LIBRARY_FUNCS_TO_INCLUDE += ['$warnOnce']
-
   if settings.MODULARIZE and not (settings.EXPORT_ES6 and not settings.SINGLE_FILE) and \
      settings.EXPORT_NAME == 'Module' and options.oformat == OFormat.HTML and \
      (options.shell_path == DEFAULT_SHELL_HTML or options.shell_path == utils.path_from_root('src/shell_minimal.html')):