Hash symbol in signatures requires parens to remain

[Smaug123]

Issue created from fantomas-ui

The removal of parens here changes the semantics, and causes some of our code to stop compiling.

Code

module Bar =
  let foo (_ : #(int seq)) = 1

Result

module Bar =
    let foo(_: #int seq) = 1

Options

Fantomas Next - 3.0.1-11/13/2019

Name	Value
IndentOnTryWith	false
IndentSpaceNum	4
KeepNewlineAfter	false
PageWidth	120
ReorderOpenDeclaration	false
SemicolonAtEndOfLine	false
SpaceAfterComma	false
SpaceAfterSemicolon	false
SpaceAroundDelimiter	false
SpaceBeforeArgument	false
SpaceBeforeColon	false
StrictMode	false