[wasm] Add flag to validate asm.js modules.

src/flag-definitions.h

 // Copyright 2012 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.
 
 // This file defines all of the flags.  It is separated into different section,
 // for Debug, Release, Logging and Profiling, etc.  To add a new flag, find the
 // correct section, and use one of the DEFINE_ macros, without a trailing ';'.
 //
 // This include does not have a guard, because it is a template-style include,
 // which can be included multiple times in different modes.  It expects to have
@@ skipping 457 matching lines @@
 DEFINE_BOOL(trace_wasm_compiler, false, "trace compiling of wasm code")
 DEFINE_INT(trace_wasm_ast_start, 0,
            "start function for WASM AST trace (inclusive)")
 DEFINE_INT(trace_wasm_ast_end, 0, "end function for WASM AST trace (exclusive)")
 DEFINE_INT(skip_compiling_wasm_funcs, 0, "start compiling at function N")
 DEFINE_BOOL(wasm_break_on_decoder_error, false,
             "debug break when wasm decoder encounters an error")
 DEFINE_BOOL(wasm_loop_assignment_analysis, true,
             "perform loop assignment analysis for WASM")
 
+DEFINE_BOOL(validate_asm, false, "validate asm.js modules before compiling")
 DEFINE_BOOL(enable_simd_asmjs, false, "enable SIMD.js in asm.js stdlib")
 
 DEFINE_BOOL(dump_wasm_module, false, "dump WASM module bytes")
 DEFINE_STRING(dump_wasm_module_path, NULL, "directory to dump wasm modules to")
 DEFINE_BOOL(print_wasm_code_size, false,
             "print the generated code size for each wasm module")
 
 DEFINE_INT(typed_array_max_size_in_heap, 64,
            "threshold for in-heap typed array")
 
@@ skipping 682 matching lines @@
 #undef DEFINE_ALIAS_FLOAT
 #undef DEFINE_ALIAS_ARGS
 
 #undef FLAG_MODE_DECLARE
 #undef FLAG_MODE_DEFINE
 #undef FLAG_MODE_DEFINE_DEFAULTS
 #undef FLAG_MODE_META
 #undef FLAG_MODE_DEFINE_IMPLICATIONS
 
 #undef COMMA