[wasm] Extra LEB utilities to leb-helper.h

src/wasm/ast-decoder.h

Index: src/wasm/ast-decoder.h
diff --git a/src/wasm/ast-decoder.h b/src/wasm/ast-decoder.h
index 5376e7bfdd9db7ab6e0521726b77c77e9f9013bc..cbbabe2fdc7d761ce18a3a2378d3a23893dc36a4 100644
--- a/src/wasm/ast-decoder.h
+++ b/src/wasm/ast-decoder.h
@@ -215,11 +215,6 @@ inline TreeResult BuildTFGraph(base::AccountingAllocator* allocator,
   return BuildTFGraph(allocator, builder, body);
 }
 
-enum ReadUnsignedLEB128ErrorCode { kNoError, kInvalidLEB128, kMissingLEB128 };
-
-ReadUnsignedLEB128ErrorCode ReadUnsignedLEB128Operand(const byte*, const byte*,
-                                                      int*, uint32_t*);
-
 struct AstLocalDecls {
   // The size of the encoded declarations.
   uint32_t decls_encoded_size;  // size of encoded declarations