dev-lang/ghc: add a patch to fix the build

There's a shell test with == in the bundled terminfo's ./configure.

Closes: https://bugs.gentoo.org/978912
Signed-off-by: Michael Orlitzky <mjo@gentoo.org>

dev-lang/ghc/files/ghc-9.8.4-fix-terminfo-build.patch

@@ -0,0 +1,13 @@
+diff --git a/libraries/terminfo/configure b/libraries/terminfo/configure
+index 9c66cad..30ade23 100755
+--- a/libraries/terminfo/configure
++++ b/libraries/terminfo/configure
+@@ -1821,7 +1821,7 @@ if test "x$curses_libraries" != "xNONE"; then
+   TERMINFO_LIB_DIRS=$curses_libraries
+ fi
+ 
+-if test "x$curses_library" == "xNONE"; then
++if test "x$curses_library" = "xNONE"; then
+ ac_ext=c
+ ac_cpp='$CPP $CPPFLAGS'
+ ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'

dev-lang/ghc/ghc-9.8.4-r1.ebuild

@@ -589,6 +589,9 @@ src_prepare() {
 
 	cd "${S}" # otherwise eapply will break
 
+	# https://bugs.gentoo.org/978912
+	eapply "${FILESDIR}/ghc-9.8.4-fix-terminfo-build.patch"
+
 	eapply "${FILESDIR}"/${PN}-8.10.1-allow-cross-bootstrap.patch
 
 	# https://gitlab.haskell.org/ghc/ghc/-/issues/22954