Compress deopt instructions in memory using variable length encoding.

runtime/vm/service_test.cc

Index: runtime/vm/service_test.cc
diff --git a/runtime/vm/service_test.cc b/runtime/vm/service_test.cc
index 368b6d806a752bd5bb45b069126b7e9981d885c3..b3a70f4a0633c6e4eb4d3b5c810e92ff7a3eef30 100644
--- a/runtime/vm/service_test.cc
+++ b/runtime/vm/service_test.cc
@@ -290,7 +290,7 @@ TEST_CASE(Service_Objects) {
   handler.filterMsg("size");
   EXPECT_STREQ(
       "{\"type\":\"bool\","
-      "\"class\":{\"type\":\"@Class\",\"id\":\"classes\\/46\","
+      "\"class\":{\"type\":\"@Class\",\"id\":\"classes\\/45\","
       "\"name\":\"bool\"},"
       "\"fields\":[],\"id\":\"objects\\/bool-true\","
       "\"valueAsString\":\"true\"}",
@@ -304,7 +304,7 @@ TEST_CASE(Service_Objects) {
   handler.filterMsg("_vmName");
   EXPECT_STREQ(
       "{\"type\":\"int\",\"_vmType\":\"Smi\","
-      "\"class\":{\"type\":\"@Class\",\"id\":\"classes\\/42\","
+      "\"class\":{\"type\":\"@Class\",\"id\":\"classes\\/41\","
       "\"name\":\"_Smi\",},"
       "\"fields\":[],"
       "\"id\":\"objects\\/int-123\","