Remove a couple of methods from Fd

Either their signature will likely change once they are actually
implemented in one of the Fd impls or they are not strictly necessary to
exist.

src/fd.ts

@@ -2,18 +2,12 @@
 import * as wasi from "./wasi_defs.js";
 
 export abstract class Fd {
-  fd_advise(offset: bigint, len: bigint, advice: number): number {
-    return wasi.ERRNO_SUCCESS;
-  }
   fd_allocate(offset: bigint, len: bigint): number {
     return wasi.ERRNO_NOTSUP;
   }
   fd_close(): number {
     return 0;
   }
-  fd_datasync(): number {
-    return wasi.ERRNO_NOTSUP;
-  }
   fd_fdstat_get(): { ret: number; fdstat: wasi.Fdstat | null } {
     return { ret: wasi.ERRNO_NOTSUP, fdstat: null };
   }
@@ -120,9 +114,6 @@ export abstract class Fd {
   path_rename(old_path: string, new_fd: number, new_path: string): number {
     return wasi.ERRNO_NOTSUP;
   }
-  path_symlink(old_path: string, new_path: string): number {
-    return wasi.ERRNO_NOTSUP;
-  }
   path_unlink_file(path: string): number {
     return wasi.ERRNO_NOTSUP;
   }

src/fs_opfs.ts

@@ -142,12 +142,8 @@ export class OpenSyncOPFSFile extends Fd {
     return { ret: wasi.ERRNO_SUCCESS, nwritten: n };
   }
 
-  fd_datasync(): number {
+  fd_sync(): number {
     this.file.handle.flush();
     return wasi.ERRNO_SUCCESS;
   }
-
-  fd_sync(): number {
-    return this.fd_datasync();
-  }
 }

src/wasi.ts

@@ -184,12 +184,15 @@ export default class WASI {
 
       fd_advise(
         fd: number,
+        // eslint-disable-next-line @typescript-eslint/no-unused-vars
         offset: bigint,
+        // eslint-disable-next-line @typescript-eslint/no-unused-vars
         len: bigint,
+        // eslint-disable-next-line @typescript-eslint/no-unused-vars
         advice: number,
       ): number {
         if (self.fds[fd] != undefined) {
-          return self.fds[fd].fd_advise(offset, len, advice);
+          return wasi.ERRNO_SUCCESS;
         } else {
           return wasi.ERRNO_BADF;
         }
@@ -212,7 +215,7 @@ export default class WASI {
       },
       fd_datasync(fd: number): number {
         if (self.fds[fd] != undefined) {
-          return self.fds[fd].fd_datasync();
+          return self.fds[fd].fd_sync();
         } else {
           return wasi.ERRNO_BADF;
         }
@@ -788,13 +791,15 @@ export default class WASI {
       ): number {
         const buffer8 = new Uint8Array(self.inst.exports.memory.buffer);
         if (self.fds[fd] != undefined) {
+          // eslint-disable-next-line @typescript-eslint/no-unused-vars
           const old_path = new TextDecoder("utf-8").decode(
             buffer8.slice(old_path_ptr, old_path_ptr + old_path_len),
           );
+          // eslint-disable-next-line @typescript-eslint/no-unused-vars
           const new_path = new TextDecoder("utf-8").decode(
             buffer8.slice(new_path_ptr, new_path_ptr + new_path_len),
           );
-          return self.fds[fd].path_symlink(old_path, new_path);
+          return wasi.ERRNO_NOTSUP;
         } else {
           return wasi.ERRNO_BADF;
         }