[wasm] Int64Lowering of I64Shl on ia32.

src/compiler/ia32/code-generator-ia32.cc

Index: src/compiler/ia32/code-generator-ia32.cc
diff --git a/src/compiler/ia32/code-generator-ia32.cc b/src/compiler/ia32/code-generator-ia32.cc
index 1f61af8abf9c14f56ff27a7eb4dae6bcd8b40f6a..f81f5760632b95bb63938443e3efbb54b06130a5 100644
--- a/src/compiler/ia32/code-generator-ia32.cc
+++ b/src/compiler/ia32/code-generator-ia32.cc
@@ -632,6 +632,14 @@ void CodeGenerator::AssembleArchInstruction(Instruction* instr) {
         __ sar_cl(i.OutputOperand());
       }
       break;
+    case kIA32PairShl:
+      if (HasImmediateInput(instr, 2)) {
+        __ PairShl(i.InputRegister(1), i.InputRegister(0), i.InputInt6(2));
+      } else {
+        // Shift has been loaded into CL by the register allocator.
+        __ PairShl_cl(i.InputRegister(1), i.InputRegister(0));
+      }
+      break;
     case kIA32Ror:
       if (HasImmediateInput(instr, 1)) {
         __ ror(i.OutputOperand(), i.InputInt5(1));