[wasm-simd][scalar-lowering] Lower simd before int64

SIMD lowering can result in int64 nodes (from i64x2), and int64 nodes
won't create SIMD nodes. So run SIMD lowering first, then int64
lowering.

Bug: v8:10507
Change-Id: Id720d98eda0bcd9ab441df687f974fd84bf9118c
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2393497Reviewed-by: Bill Budge <bbudge@chromium.org>
Commit-Queue: Zhi An Ng <zhin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#69756}

src/compiler/wasm-compiler.cc

@@ -7420,8 +7420,8 @@ bool BuildGraphForWasmFunction(AccountingAllocator* allocator,
     return false;
   }
 
-  builder.LowerInt64(WasmWrapperGraphBuilder::kCalledFromWasm);
-
+  // Lower SIMD first, i64x2 nodes will be lowered to int64 nodes, then int64
+  // lowering will take care of them.
   if (builder.has_simd() &&
       (!CpuFeatures::SupportsWasmSimd128() || env->lower_simd)) {
     SimdScalarLowering(
@@ -7430,6 +7430,8 @@ bool BuildGraphForWasmFunction(AccountingAllocator* allocator,
         .LowerGraph();
   }
 
+  builder.LowerInt64(WasmWrapperGraphBuilder::kCalledFromWasm);
+
   if (func_index >= FLAG_trace_wasm_ast_start &&
       func_index < FLAG_trace_wasm_ast_end) {
     PrintRawWasmCode(allocator, func_body, env->module, wasm::kPrintLocals);