Support latest PXT with GC (#1798)

* Enable gc and basic compilation fixes

* Add missing GC stuff

* Set microbit-dal version

* Disable jacdac in servo

* UTF fixes

* TS build fixes

* Auto-generated files update

* We only seem to have that much

* Fix for new new compiler

* Account for uninitialized scheduler

* Intialize memory allocator

* bump references

* updated package

* Set image tag, requires https://github.com/Microsoft/pxt/pull/5262

* updated project summaries

* Fixing block tests

libs/core/enums.d.ts

@@ -22,13 +22,8 @@
     }
 
 
-    declare const enum ValType {
-    Undefined = 0,
-    Boolean = 1,
-    Number = 2,
-    String = 3,
-    Object = 4,
-    Function = 5,
+    declare const enum PerfCounters {
+    GC = 0,
     }
 declare namespace images {
 }