Fix regression incorrectly advertising TH support
authorHerbert Valerio Riedel <hvr@gnu.org>
Sat, 16 Feb 2019 21:08:46 +0000 (22:08 +0100)
committerMarge Bot <ben+marge-bot@smart-cactus.org>
Sun, 24 Feb 2019 02:43:58 +0000 (21:43 -0500)
commitee284b854e514685036dc21a1ee61241c76d14b5
tree085d8ea2b95729c6706cd023680e3f27e0ec45e9
parente61f6e35e2fffb1e82e9559852481010fe84d8d3
Fix regression incorrectly advertising TH support

`--supported-languages` must only advertise language extensions
which are supported by the compiler in order for tooling such
as Cabal relying on this signalling not to behave incorrectly.

Fixes #16331
compiler/main/DynFlags.hs