File.realPath().

Not tested yet, because we can't create symlinks from Wren and I don't
want to check symlinks into the repo, but it seems to do the right
thing.

src/cli/modules.c

@@ -17,6 +17,7 @@ extern void fileSizePath(WrenVM* vm);
 extern void fileClose(WrenVM* vm);
 extern void fileDescriptor(WrenVM* vm);
 extern void fileReadBytes(WrenVM* vm);
+extern void fileRealPath(WrenVM* vm);
 extern void fileSize(WrenVM* vm);
 extern void fileStat(WrenVM* vm);
 extern void fileWriteBytes(WrenVM* vm);
@@ -115,6 +116,7 @@ static ModuleRegistry modules[] =
       FINALIZER(fileFinalize)
       STATIC_METHOD("delete_(_,_)", fileDelete)
       STATIC_METHOD("open_(_,_,_)", fileOpen)
+      STATIC_METHOD("realPath_(_,_)", fileRealPath)
       STATIC_METHOD("sizePath_(_,_)", fileSizePath)
       METHOD("close_(_)", fileClose)
       METHOD("descriptor", fileDescriptor)