Bump major Tasty version

Author: odersky

compiler/src/dotty/tools/dotc/core/tasty/TastyFormat.scala

@@ -229,7 +229,7 @@ Standard Section: "Positions" Assoc*
 object TastyFormat {
 
   final val header = Array(0x5C, 0xA1, 0xAB, 0x1F)
-  val MajorVersion = 1
+  val MajorVersion = 2
   val MinorVersion = 0
 
   // Name tags
@@ -391,8 +391,8 @@ object TastyFormat {
   final val LAMBDAtpt = 173
   final val PARAMtype = 174
   final val ANNOTATION = 175
-  final val TERMREFin = 177
-  final val TYPEREFin = 178
+  final val TERMREFin = 176
+  final val TYPEREFin = 177
 
   final val firstSimpleTreeTag = UNITconst
   final val firstNatTreeTag = SHARED