Don't inline methods that only throw.

pkg/compiler/lib/src/cps_ir/inline.dart

Index: pkg/compiler/lib/src/cps_ir/inline.dart
diff --git a/pkg/compiler/lib/src/cps_ir/inline.dart b/pkg/compiler/lib/src/cps_ir/inline.dart
index cc046eec2c56c6588041c26cee5f3c652ae5b072..2771aefc89cef8aa6176d703f5beb7e88d28c4b2 100644
--- a/pkg/compiler/lib/src/cps_ir/inline.dart
+++ b/pkg/compiler/lib/src/cps_ir/inline.dart
@@ -372,6 +372,13 @@ class InliningVisitor extends TrampolineRecursiveVisitor {
       return null;
     }
 
+    // Don't inline methods that never return. They are usually helper functions
+    // that throw an exception.
+    if (invoke.type.isEmpty && !invoke.type.isNullable) {
+      // TODO(sra): It would be ok to inline if doing so was shrinking.
+      return null;
+    }
+
     Reference<Primitive> dartReceiver = invoke.dartReceiverReference;
     TypeMask abstractReceiver =
         dartReceiver == null ? null : abstractType(dartReceiver);