[wasm] Rework encoding of local declarations.

test/mjsunit/wasm/verify-function-simple.js

Index: test/mjsunit/wasm/verify-function-simple.js
diff --git a/test/mjsunit/wasm/verify-function-simple.js b/test/mjsunit/wasm/verify-function-simple.js
index c4d51c7423ba2781b9b847c33e92e04cd0039ab0..ef87d0e136429f8121c1e8ce4c6e16c26e3296e8 100644
--- a/test/mjsunit/wasm/verify-function-simple.js
+++ b/test/mjsunit/wasm/verify-function-simple.js
@@ -9,10 +9,7 @@ load("test/mjsunit/wasm/wasm-constants.js");
 try {
   var data = bytes(
       0,       kAstStmt,  // signature
-      3,       0,         // local int32 count
-      4,       0,         // local int64 count
-      5,       0,         // local float32 count
-      6,       0,         // local float64 count
+      kDeclNoLocals,      // --
       kExprNop            // body
   );
 
@@ -27,10 +24,7 @@ var threw = false;
 try {
   var data = bytes(
       0,       kAstI32,   // signature
-      2,       0,         // local int32 count
-      3,       0,         // local int64 count
-      4,       0,         // local float32 count
-      5,       0,         // local float64 count
+      kDeclNoLocals,      // --
       kExprBlock, 2, kExprNop, kExprNop  // body
   );