[wasm] Fix -Wsign-compare warnings.

test/unittests/wasm/ast-decoder-unittest.cc

 // 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.
 
 #include "test/unittests/test-utils.h"
 
 #include "src/v8.h"
 
 #include "test/common/wasm/test-signatures.h"
 
@@ skipping 1166 matching lines @@
       {kExprI64LoadMem16U, 1},  // --
       {kExprI64LoadMem16S, 1},  // --
       {kExprI64LoadMem32U, 2},  // --
       {kExprI64LoadMem32S, 2},  // --
       {kExprI32LoadMem, 2},     // --
       {kExprI64LoadMem, 3},     // --
       {kExprF32LoadMem, 2},     // --
       {kExprF64LoadMem, 3},     // --
   };
 
-  for (int i = 0; i < arraysize(values); i++) {
+  for (size_t i = 0; i < arraysize(values); i++) {
     for (byte alignment = 0; alignment <= 4; alignment++) {
       byte code[] = {WASM_ZERO, static_cast<byte>(values[i].instruction),
                      alignment, ZERO_OFFSET, WASM_DROP};
       if (static_cast<uint32_t>(alignment) <= values[i].maximum_aligment) {
         EXPECT_VERIFIES_C(v_i, code);
       } else {
         EXPECT_FAILURE_C(v_i, code);
       }
     }
   }
@@ skipping 492 matching lines @@
       {kExprI32AsmjsStoreMem16, sigs.i_ii()},
       {kExprI32AsmjsStoreMem, sigs.i_ii()},
       {kExprF32AsmjsStoreMem, &sig_f_if},
       {kExprF64AsmjsStoreMem, &sig_d_id},
   };
 
   {
     TestModuleEnv module_env;
     module = &module_env;
     module->origin = kAsmJsOrigin;
-    for (int i = 0; i < arraysize(AsmJsBinOps); i++) {
+    for (size_t i = 0; i < arraysize(AsmJsBinOps); i++) {
       TestBinop(AsmJsBinOps[i].op, AsmJsBinOps[i].sig);
     }
   }
 
   {
     TestModuleEnv module_env;
     module = &module_env;
     module->origin = kWasmOrigin;
-    for (int i = 0; i < arraysize(AsmJsBinOps); i++) {
+    for (size_t i = 0; i < arraysize(AsmJsBinOps); i++) {
       byte code[] = {
           WASM_BINOP(AsmJsBinOps[i].op, WASM_GET_LOCAL(0), WASM_GET_LOCAL(1))};
       EXPECT_FAILURE_SC(AsmJsBinOps[i].sig, code);
     }
   }
 }
 
 TEST_F(AstDecoderTest, AsmJsUnOpsCheckOrigin) {
   LocalType float32int32[] = {kAstF32, kAstI32};
   FunctionSig sig_f_i(1, 1, float32int32);
@@ skipping 18 matching lines @@
                     {kExprF32AsmjsLoadMem, &sig_f_i},
                     {kExprF64AsmjsLoadMem, &sig_d_i},
                     {kExprI32AsmjsSConvertF32, sigs.i_f()},
                     {kExprI32AsmjsUConvertF32, sigs.i_f()},
                     {kExprI32AsmjsSConvertF64, sigs.i_d()},
                     {kExprI32AsmjsUConvertF64, sigs.i_d()}};
   {
     TestModuleEnv module_env;
     module = &module_env;
     module->origin = kAsmJsOrigin;
-    for (int i = 0; i < arraysize(AsmJsUnOps); i++) {
+    for (size_t i = 0; i < arraysize(AsmJsUnOps); i++) {
       TestUnop(AsmJsUnOps[i].op, AsmJsUnOps[i].sig);
     }
   }
 
   {
     TestModuleEnv module_env;
     module = &module_env;
     module->origin = kWasmOrigin;
-    for (int i = 0; i < arraysize(AsmJsUnOps); i++) {
+    for (size_t i = 0; i < arraysize(AsmJsUnOps); i++) {
       byte code[] = {WASM_UNOP(AsmJsUnOps[i].op, WASM_GET_LOCAL(0))};
       EXPECT_FAILURE_SC(AsmJsUnOps[i].sig, code);
     }
   }
 }
 
 TEST_F(AstDecoderTest, BreakEnd) {
   EXPECT_VERIFIES(
       i_i, WASM_BLOCK_I(WASM_I32_ADD(WASM_BRV(0, WASM_ZERO), WASM_ZERO)));
   EXPECT_VERIFIES(
@@ skipping 938 matching lines @@
   iter.next();
   EXPECT_TRUE(iter.has_next());
   EXPECT_EQ(kExprI8Const, iter.current());
   iter.next();
   EXPECT_FALSE(iter.has_next());
 }
 
 }  // namespace wasm
 }  // namespace internal
 }  // namespace v8