Add wasm internal opcodes for asm.js stdlib functions we're missing.

src/wasm/wasm-opcodes.cc

Index: src/wasm/wasm-opcodes.cc
diff --git a/src/wasm/wasm-opcodes.cc b/src/wasm/wasm-opcodes.cc
index a609e032611ce8633ee5c148882dfb0df9503e50..ab0d68851aeaa86f290ad2e77036e2c5a03dd228 100644
--- a/src/wasm/wasm-opcodes.cc
+++ b/src/wasm/wasm-opcodes.cc
@@ -66,6 +66,7 @@ static void InitSigTable() {
 #define SET_SIG_TABLE(name, opcode, sig) \
   kSimpleExprSigTable[opcode] = static_cast<int>(kSigEnum_##sig) + 1;
   FOREACH_SIMPLE_OPCODE(SET_SIG_TABLE);
+  FOREACH_ASMJS_COMPAT_OPCODE(SET_SIG_TABLE);
 #undef SET_SIG_TABLE
 }