Compiler bug for updateDynamic invocations within expressions #5733
Description
Problem with updateDynamic:
\
If a dynamic field assignment is invoked within an expression (the type of the assignment invocation depends on the result type of method updateDynamic), then the compiler reports the error reassignment to val.
scala> val foo = new A // A implements selectDynamic and updateDynamic
foo: A = A@71933d6c
scala> foo.xxx = 3
foo.xxx: Any = 3
scala> foo.xxx
res0: Any = 3
scala> println(foo.xxx = 3)
<console>:12: error: reassignment to val
println(foo.xxx = 3)
^
scala> val x = (foo.xxx = 3) == ()
<console>:11: error: reassignment to val
val x = (foo.xxx = 3) == ()
^