[WASM SIMD] Implement packing and unpacking integer conversions.

src/compiler/machine-operator.h

Index: src/compiler/machine-operator.h
diff --git a/src/compiler/machine-operator.h b/src/compiler/machine-operator.h
index 8ea05fb53f084db88cd867dd890465bdc4b34ced..b0b78e560ba040cde7efd75bbcc08862a5596f57 100644
--- a/src/compiler/machine-operator.h
+++ b/src/compiler/machine-operator.h
@@ -465,6 +465,8 @@ class V8_EXPORT_PRIVATE MachineOperatorBuilder final
   const Operator* I32x4ExtractLane(int32_t);
   const Operator* I32x4ReplaceLane(int32_t);
   const Operator* I32x4SConvertF32x4();
+  const Operator* I32x4SConvertI16x8Low();
+  const Operator* I32x4SConvertI16x8High();
   const Operator* I32x4Neg();
   const Operator* I32x4Shl(int32_t);
   const Operator* I32x4ShrS(int32_t);
@@ -479,6 +481,8 @@ class V8_EXPORT_PRIVATE MachineOperatorBuilder final
   const Operator* I32x4LeS();
 
   const Operator* I32x4UConvertF32x4();
+  const Operator* I32x4UConvertI16x8Low();
+  const Operator* I32x4UConvertI16x8High();
   const Operator* I32x4ShrU(int32_t);
   const Operator* I32x4MinU();
   const Operator* I32x4MaxU();
@@ -488,9 +492,12 @@ class V8_EXPORT_PRIVATE MachineOperatorBuilder final
   const Operator* I16x8Splat();
   const Operator* I16x8ExtractLane(int32_t);
   const Operator* I16x8ReplaceLane(int32_t);
+  const Operator* I16x8SConvertI8x16Low();
+  const Operator* I16x8SConvertI8x16High();
   const Operator* I16x8Neg();
   const Operator* I16x8Shl(int32_t);
   const Operator* I16x8ShrS(int32_t);
+  const Operator* I16x8SConvertI32x4();
   const Operator* I16x8Add();
   const Operator* I16x8AddSaturateS();
   const Operator* I16x8Sub();
@@ -503,7 +510,10 @@ class V8_EXPORT_PRIVATE MachineOperatorBuilder final
   const Operator* I16x8LtS();
   const Operator* I16x8LeS();
 
+  const Operator* I16x8UConvertI8x16Low();
+  const Operator* I16x8UConvertI8x16High();
   const Operator* I16x8ShrU(int32_t);
+  const Operator* I16x8UConvertI32x4();
   const Operator* I16x8AddSaturateU();
   const Operator* I16x8SubSaturateU();
   const Operator* I16x8MinU();
@@ -517,6 +527,7 @@ class V8_EXPORT_PRIVATE MachineOperatorBuilder final
   const Operator* I8x16Neg();
   const Operator* I8x16Shl(int32_t);
   const Operator* I8x16ShrS(int32_t);
+  const Operator* I8x16SConvertI16x8();
   const Operator* I8x16Add();
   const Operator* I8x16AddSaturateS();
   const Operator* I8x16Sub();
@@ -530,6 +541,7 @@ class V8_EXPORT_PRIVATE MachineOperatorBuilder final
   const Operator* I8x16LeS();
 
   const Operator* I8x16ShrU(int32_t);
+  const Operator* I8x16UConvertI16x8();
   const Operator* I8x16AddSaturateU();
   const Operator* I8x16SubSaturateU();
   const Operator* I8x16MinU();