[wasm][eh] Fix delegate opcode

Replace 0x16 with 0x18 for the delegate opcode, to avoid a conflict with
the function reference proposal.
See https://github.com/WebAssembly/exception-handling/issues/145

R=clemensb@chromium.org

Bug: v8:8091
Change-Id: Ib012f8680dfece200973e18fdf6c82877f10d5de
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2632604Reviewed-by: Clemens Backes <clemensb@chromium.org>
Commit-Queue: Thibaud Michaud <thibaudm@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72118}

src/wasm/wasm-opcodes.h

@@ -44,10 +44,10 @@ bool V8_EXPORT_PRIVATE IsJSCompatibleSignature(const FunctionSig* sig,
   V(BrIf, 0x0d, _)                              \
   V(BrTable, 0x0e, _)                           \
   V(Return, 0x0f, _)                            \
-  V(Delegate, 0x16, _ /* eh_prototype */)       \
   V(Let, 0x17, _ /* typed_funcref prototype */) \
+  V(Delegate, 0x18, _ /* eh_prototype */)       \
   V(BrOnNull, 0xd4, _ /* gc prototype */)       \
-  V(NopForTestingUnsupportedInLiftoff, 0x18, _)
+  V(NopForTestingUnsupportedInLiftoff, 0x19, _)
 
 // Constants, locals, globals, and calls.
 #define FOREACH_MISC_OPCODE(V)                            \

test/debugger/debug/wasm/debug-enabled-tier-down-wasm-unsupported-liftoff.js

@@ -11,7 +11,7 @@ load('test/mjsunit/wasm/wasm-module-builder.js');
 
 // Create a simple Wasm module.
 function create_builder(i) {
-  const kExprNopForTestingUnsupportedInLiftoff = 0x18;
+  const kExprNopForTestingUnsupportedInLiftoff = 0x19;
   const builder = new WasmModuleBuilder();
   builder.addFunction('main', kSig_i_i)
       .addBody([

test/mjsunit/wasm/wasm-module-builder.js

@@ -228,8 +228,8 @@ const kWasmOpcodes = {
   'ReturnCallIndirect': 0x13,
   'CallRef': 0x14,
   'ReturnCallRef': 0x15,
-  'Delegate': 0x16,
   'Let': 0x17,
+  'Delegate': 0x18,
   'Drop': 0x1a,
   'Select': 0x1b,
   'SelectWithType': 0x1c,