'+=' etc for all floating point types

tests/reject/tenummix.nim

@@ -0,0 +1,9 @@
+discard """
+  errormsg: "type mismatch"
+"""
+
+type
+  TE1 = enum eA, eB
+  TE2 = enum eC, eD
+  
+assert eA != eC

tests/run/tdumptree.nim

@@ -1,4 +1,5 @@
 discard """
+disabled: true
 output: '''StmtList
   VarSection
     IdentDefs
@@ -11,6 +12,8 @@ output: '''StmtList
         IntLit 56'''
 """
 
+# disabled; can't work as the output is done by the compiler
+
 import macros
 
 #emit("type\n  TFoo = object\n    bar: int")