[wasm] Remove the module environment and signature as arguments to OpcodeArity.

src/wasm/ast-decoder.h

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_WASM_AST_DECODER_H_
 #define V8_WASM_AST_DECODER_H_
 
 #include "src/signature.h"
 #include "src/wasm/decoder.h"
 #include "src/wasm/wasm-opcodes.h"
@@ skipping 244 matching lines @@
 };
 
 bool DecodeLocalDecls(AstLocalDecls& decls, const byte* start, const byte* end);
 BitVector* AnalyzeLoopAssignmentForTesting(Zone* zone, size_t num_locals,
                                            const byte* start, const byte* end);
 
 // Computes the length of the opcode at the given address.
 int OpcodeLength(const byte* pc, const byte* end);
 
 // Computes the arity (number of sub-nodes) of the opcode at the given address.
-int OpcodeArity(ModuleEnv* module, FunctionSig* sig, const byte* pc,
-                const byte* end);
+int OpcodeArity(const byte* pc, const byte* end);
+
 }  // namespace wasm
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_WASM_AST_DECODER_H_