Revert "Use interceptors for is-checks (version 2)."

pkg/compiler/lib/src/tree_ir/optimization/logical_rewriter.dart

Index: pkg/compiler/lib/src/tree_ir/optimization/logical_rewriter.dart
diff --git a/pkg/compiler/lib/src/tree_ir/optimization/logical_rewriter.dart b/pkg/compiler/lib/src/tree_ir/optimization/logical_rewriter.dart
index 4f0be4ad41428b4d8f3bb5a075004aaa377178a1..bc49dc750fd47f5d27e7d8f210fd3d9f9ac60764 100644
--- a/pkg/compiler/lib/src/tree_ir/optimization/logical_rewriter.dart
+++ b/pkg/compiler/lib/src/tree_ir/optimization/logical_rewriter.dart
@@ -335,13 +335,8 @@ class LogicalRewriter extends RecursiveTransformer
     return isTrue(e) ||
            isFalse(e) ||
            e is Not ||
-           e is LogicalOperator && isBooleanValuedLogicalOperator(e) ||
-           e is ApplyBuiltinOperator && operatorReturnsBool(e.operator) ||
-           e is TypeOperator && isBooleanValuedTypeOperator(e);
-  }
-
-  bool isBooleanValuedLogicalOperator(LogicalOperator e) {
-    return isBooleanValued(e.left) && isBooleanValued(e.right);
+           e is LogicalOperator ||
+           e is ApplyBuiltinOperator && operatorReturnsBool(e.operator);
   }
 
   /// True if the given operator always returns `true` or `false`.
@@ -366,10 +361,6 @@ class LogicalRewriter extends RecursiveTransformer
     }
   }
 
-  bool isBooleanValuedTypeOperator(TypeOperator e) {
-    return e.isTypeTest;
-  }
-
   BuiltinOperator negateBuiltin(BuiltinOperator operator) {
     switch (operator) {
       case BuiltinOperator.StrictEq: return BuiltinOperator.StrictNeq;
@@ -561,3 +552,4 @@ class LogicalRewriter extends RecursiveTransformer
     --node.variable.readCount;
   }
 }
+