Fix GhcThreaded setting

This adopts a patch from NetBSD's packaging fixing the `GhcThreaded`
option of the make build system. In addition we introduce a `ghcThreaded`
option in hadrian's `Flavour` type.

Also fix Hadrian's treatment of the `Use Threaded` entry in `settings`.
Previously it would incorrectly claim `Use Threaded = True` if we were
building the `threaded` runtime way. However, this is inconsistent with
the `make` build system, which defines it to be whether the `ghc`
executable is linked against the threaded runtime.

Fixes #17692.

1 files changed, 2 insertions, 0 deletions

diff --git a/hadrian/doc/user-settings.md b/hadrian/doc/user-settings.md
index 064918efe2..de0d452fd5 100644
--- a/hadrian/doc/user-settings.md
+++ b/hadrian/doc/user-settings.md
@@ -35,6 +35,8 @@ data Flavour = Flavour {
     ghcProfiled :: Bool,
     -- | Build GHC with debug information.
     ghcDebugged :: Bool
+    -- | Build the GHC executable against the threaded runtime system.
+    ghcThreaded :: Bool,
     -- | Whether to build docs and which ones
     --   (haddocks, user manual, haddock manual)
     ghcDocs :: Action DocTargets }