[turboshaft] InstructionSelector: Enable behind --turboshaft-future

This enables the turboshaft ISel for arm64 in --turboshaft-future
configs. It also adds it for wasm on x64 which wasn't enabled yet.

Bug: v8:12783
Change-Id: I5a816fe97beec8fc83c922ddd7f274c89ff61820
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/5077389
Reviewed-by: Darius Mercadier <[email protected]>
Commit-Queue: Matthias Liedtke <[email protected]>
Cr-Commit-Position: refs/heads/main@{#91324}

src/flags/flag-definitions.h

@@ -1279,9 +1279,13 @@ DEFINE_WEAK_IMPLICATION(turboshaft_future, turboshaft_load_elimination)
 DEFINE_WEAK_IMPLICATION(turboshaft_future, turboshaft_machine_lowering_opt)
 DEFINE_WEAK_IMPLICATION(turboshaft_future, turboshaft_loop_unrolling)
 DEFINE_WEAK_IMPLICATION(turboshaft_future, turboshaft_loop_peeling)
-#ifdef V8_TARGET_ARCH_X64
+#if V8_TARGET_ARCH_X64 or V8_TARGET_ARCH_ARM64
 DEFINE_WEAK_IMPLICATION(turboshaft_future, turboshaft_instruction_selection)
+DEFINE_WEAK_IMPLICATION(turboshaft_future,
+                        turboshaft_wasm_instruction_selection_experimental)
 #endif
+DEFINE_WEAK_IMPLICATION(turboshaft_future,
+                        turboshaft_wasm_instruction_selection_staged)
 
 #ifdef DEBUG
 DEFINE_UINT64(turboshaft_opt_bisect_limit, std::numeric_limits<uint64_t>::max(),