[WASM] Eliminate SIMD boolean vector types.

src/machine-type.h

Index: src/machine-type.h
diff --git a/src/machine-type.h b/src/machine-type.h
index 64c6a27dcbf87b46b0e4f780f728e3902e506659..fddc11cb1956c82e2ea95f13ab5d8bf8c8322a1b 100644
--- a/src/machine-type.h
+++ b/src/machine-type.h
@@ -29,11 +29,8 @@ enum class MachineRepresentation {
   kFloat32,
   kFloat64,
   kSimd128,
-  kSimd1x4,  // SIMD boolean vector types.
-  kSimd1x8,
-  kSimd1x16,
   kFirstFPRepresentation = kFloat32,
-  kLastRepresentation = kSimd1x16
+  kLastRepresentation = kSimd128
 };
 
 static_assert(static_cast<int>(MachineRepresentation::kLastRepresentation) <
@@ -130,16 +127,6 @@ class MachineType {
   static MachineType Simd128() {
     return MachineType(MachineRepresentation::kSimd128, MachineSemantic::kNone);
   }
-  static MachineType Simd1x4() {
-    return MachineType(MachineRepresentation::kSimd1x4, MachineSemantic::kNone);
-  }
-  static MachineType Simd1x8() {
-    return MachineType(MachineRepresentation::kSimd1x8, MachineSemantic::kNone);
-  }
-  static MachineType Simd1x16() {
-    return MachineType(MachineRepresentation::kSimd1x16,
-                       MachineSemantic::kNone);
-  }
   static MachineType Pointer() {
     return MachineType(PointerRepresentation(), MachineSemantic::kNone);
   }
@@ -186,16 +173,6 @@ class MachineType {
   static MachineType RepSimd128() {
     return MachineType(MachineRepresentation::kSimd128, MachineSemantic::kNone);
   }
-  static MachineType RepSimd1x4() {
-    return MachineType(MachineRepresentation::kSimd1x4, MachineSemantic::kNone);
-  }
-  static MachineType RepSimd1x8() {
-    return MachineType(MachineRepresentation::kSimd1x8, MachineSemantic::kNone);
-  }
-  static MachineType RepSimd1x16() {
-    return MachineType(MachineRepresentation::kSimd1x16,
-                       MachineSemantic::kNone);
-  }
   static MachineType RepTagged() {
     return MachineType(MachineRepresentation::kTagged, MachineSemantic::kNone);
   }
@@ -224,12 +201,6 @@ class MachineType {
         return MachineType::Float64();
       case MachineRepresentation::kSimd128:
         return MachineType::Simd128();
-      case MachineRepresentation::kSimd1x4:
-        return MachineType::Simd1x4();
-      case MachineRepresentation::kSimd1x8:
-        return MachineType::Simd1x8();
-      case MachineRepresentation::kSimd1x16:
-        return MachineType::Simd1x16();
       case MachineRepresentation::kTagged:
         return MachineType::AnyTagged();
       case MachineRepresentation::kTaggedSigned: