Revert "Enable full type-checks in checked mode."

sdk/lib/_internal/compiler/implementation/ssa/nodes.dart

Index: sdk/lib/_internal/compiler/implementation/ssa/nodes.dart
diff --git a/sdk/lib/_internal/compiler/implementation/ssa/nodes.dart b/sdk/lib/_internal/compiler/implementation/ssa/nodes.dart
index 2f182a2cab9580ea2a707936d6df2a4e2b63322f..592dfa1b67ed01b83ac272355212b62baf56aa58 100644
--- a/sdk/lib/_internal/compiler/implementation/ssa/nodes.dart
+++ b/sdk/lib/_internal/compiler/implementation/ssa/nodes.dart
@@ -1086,8 +1086,6 @@ abstract class HInstruction implements Spannable {
     } else if (kind == HTypeConversion.BOOLEAN_CONVERSION_CHECK) {
       // Boolean conversion checks work on non-nullable booleans.
       return new HTypeConversion(type, kind, HType.BOOLEAN, this);
-    } else if (kind == HTypeConversion.CHECKED_MODE_CHECK && !type.isRaw) {
-        throw 'creating compound check to $type (this = ${this})';
     } else {
       HType subtype = new HType.subtype(type, compiler);
       return new HTypeConversion(type, kind, subtype, this);
@@ -2140,6 +2138,7 @@ class HIndexAssign extends HInstruction {
   HInstruction get value => inputs[2];
 }
 
+// TODO(karlklose): use this class to represent type conversions as well.
 class HIs extends HInstruction {
   /// A check against a raw type: 'o is int', 'o is A'.
   static const int RAW_CHECK = 0;
@@ -2206,23 +2205,6 @@ class HTypeConversion extends HCheck {
     instructionType = type;
   }
 
-  HTypeConversion.withTypeRepresentation(this.typeExpression, this.kind,
-                                         HType type, HInstruction input,
-                                         HInstruction typeRepresentation)
-      : super(<HInstruction>[input, typeRepresentation]),
-        receiverTypeCheckSelector = null {
-    sourceElement = input.sourceElement;
-    instructionType = type;
-  }
-
-  bool get hasTypeRepresentation => inputs.length > 1;
-  HInstruction get typeRepresentation => inputs[1];
-
-  HInstruction convertType(Compiler compiler, DartType type, int kind) {
-    if (typeExpression == type) return this;
-    return super.convertType(compiler, type, kind);
-  }
-
   bool get isChecked => kind != NO_CHECK;
   bool get isCheckedModeCheck {
     return kind == CHECKED_MODE_CHECK