Non Int32 Enum.from_value issue

[carlhoerberg]

 ✗ crystal -v
Crystal 0.36.0 [1e6f96aef] (2021-01-26)

LLVM: 10.0.0
Default target: x86_64-unknown-linux-gnu

@[Flags]
enum F : UInt8
  A
end
F.from_value 1u8

$ crystal run f.cr
Showing last frame. Use --error-trace for full trace.

There was a problem expanding macro 'macro_139997757591040'

Code in /usr/share/crystal/src/enum.cr:357:5

 357 | {% if @type.annotation(Flags) %}
       ^
Called macro defined in /usr/share/crystal/src/enum.cr:357:5

 357 | {% if @type.annotation(Flags) %}

Which expanded to:

 > 2 | all_mask = F::All.value
 > 3 | return if all_mask & value != value
 > 4 | return new(value.to_i)
              ^--
Error: no overload matches 'F.new' with type Int32

Overloads are:
 - F.new(value : ::UInt8)

[asterite]

Regression introduced by #10145

[carlhoerberg]

Workaround suggested by @bcardiff:

struct Enum
  def self.from_value?(value : Int) : self?
    {% if @type.annotation(Flags) %}
      all_mask = {{@type}}::All.value
      return if all_mask & value != value
      return new(value)
    {% else %}
      {% for member in @type.constants %}
        return new({{@type.constant(member)}}) if {{@type.constant(member)}} == value
      {% end %}
    {% end %}
    nil
  end
end