Removed IllegalAccessException and UnsupportedOperationException.

runtime/lib/string_base.dart

Index: runtime/lib/string_base.dart
diff --git a/runtime/lib/string_base.dart b/runtime/lib/string_base.dart
index 14bd6c2dfbc37e8cc5d041866794e67bca38c6bc..45e4aa6661f027af63acc0cd67fd0bdca71e9d7a 100644
--- a/runtime/lib/string_base.dart
+++ b/runtime/lib/string_base.dart
@@ -9,7 +9,7 @@
 class _StringBase {
 
   factory _StringBase._uninstantiable() {
-    throw const UnsupportedOperationException(
+    throw new StateError(
         "_StringBase can't be instaniated");
   }
 
@@ -356,7 +356,7 @@ class _StringBase {
 
 class _OneByteString extends _StringBase implements String {
   factory _OneByteString._uninstantiable() {
-    throw const UnsupportedOperationException(
+    throw new StateError(
         "_OneByteString can only be allocated by the VM");
   }
 
@@ -374,7 +374,7 @@ class _OneByteString extends _StringBase implements String {
 
 class _TwoByteString extends _StringBase implements String {
   factory _TwoByteString._uninstantiable() {
-    throw const UnsupportedOperationException(
+    throw new StateError(
         "_TwoByteString can only be allocated by the VM");
   }
 
@@ -391,7 +391,7 @@ class _TwoByteString extends _StringBase implements String {
 
 class _FourByteString extends _StringBase implements String {
   factory _FourByteString._uninstantiable() {
-    throw const UnsupportedOperationException(
+    throw new StateError(
         "_FourByteString can only be allocated by the VM");
   }
 
@@ -408,7 +408,7 @@ class _FourByteString extends _StringBase implements String {
 
 class _ExternalOneByteString extends _StringBase implements String {
   factory _ExternalOneByteString._uninstantiable() {
-    throw const UnsupportedOperationException(
+    throw new StateError(
         "_ExternalOneByteString can only be allocated by the VM");
   }
 
@@ -425,7 +425,7 @@ class _ExternalOneByteString extends _StringBase implements String {
 
 class _ExternalTwoByteString extends _StringBase implements String {
   factory ExternalTwoByteString._uninstantiable() {
-    throw const UnsupportedOperationException(
+    throw new StateError(
         "_ExternalTwoByteString can only be allocated by the VM");
   }
 
@@ -442,7 +442,7 @@ class _ExternalTwoByteString extends _StringBase implements String {
 
 class _ExternalFourByteString extends _StringBase implements String {
   factory _ExternalFourByteString._uninstantiable() {
-    throw const UnsupportedOperationException(
+    throw new StateError(
         "ExternalFourByteString can only be allocated by the VM");
   }