Fix crash DYLINK_DEBUG=2 (#25636)

Also, cleanup error message.

Author: sbc100

src/lib/libdylink.js

@@ -234,14 +234,11 @@ var LibraryDylink = {
       var existingEntry = GOT[symName] && GOT[symName].value != 0;
       if (replace || !existingEntry) {
 #if DYLINK_DEBUG == 2
-        dbg(`updateGOT: before: ${symName} : ${GOT[symName].value}`);
+        dbg(`updateGOT: before: ${symName} : ${GOT[symName]?.value}`);
 #endif
         var newValue;
         if (typeof value == 'function') {
           newValue = {{{ to64('addFunction(value)') }}};
-#if DYLINK_DEBUG == 2
-          dbg(`updateGOT: FUNC: ${symName} : ${GOT[symName].value}`);
-#endif
         } else if (typeof value == {{{ POINTER_JS_TYPE }}}) {
           newValue = value;
         } else {
@@ -1254,9 +1251,9 @@ var LibraryDylink = {
       return loadDynamicLibrary(filename, combinedFlags, localScope, handle)
     } catch (e) {
 #if ASSERTIONS
-      err(`Error in loading dynamic library ${filename}: ${e}`);
+      err(`error loading dynamic library ${filename}: ${e}`);
 #endif
-      dlSetError(`Could not load dynamic lib: ${filename}\n${e}`);
+      dlSetError(`could not load dynamic lib: ${filename}\n${e}`);
       return 0;
     }
   },

test/test_core.py

@@ -3009,9 +3009,9 @@ def test_dlfcn_missing(self):
       '''
 
     if self.get_current_js_engine() == config.V8_ENGINE:
-      expected = "error: Could not load dynamic lib: libfoo.so\nError: Error reading file"
+      expected = "error: could not load dynamic lib: libfoo.so\nError: Error reading file"
     else:
-      expected = "error: Could not load dynamic lib: libfoo.so\nError: ENOENT: no such file or directory"
+      expected = "error: could not load dynamic lib: libfoo.so\nError: ENOENT: no such file or directory"
     self.do_run(src, expected)
 
   @needs_dylink