Remove an out-of-date comment (see #8101)

compiler/main/DynFlags.hs

@@ -883,11 +883,6 @@ opt_lc dflags = sOpt_lc (settings dflags)
 -- 'HscNothing' can be used to avoid generating any output, however, note
 -- that:
 --
---  * This will not run the desugaring step, thus no warnings generated in
---    this step will be output.  In particular, this includes warnings related
---    to pattern matching.  You can run the desugarer manually using
---    'GHC.desugarModule'.
---
 --  * If a program uses Template Haskell the typechecker may try to run code
 --    from an imported module.  This will fail if no code has been generated
 --    for this module.  You can use 'GHC.needsTemplateHaskell' to detect