emacs-27 694acda: Fix compilation on TERMINFO platforms with GCC 10

[Eli Zaretskii]

branch: emacs-27
commit 694acda5f24e356264c3f2a55a49812e02bcb49a
Author: Eli Zaretskii <eliz@gnu.org>
Commit: Eli Zaretskii <eliz@gnu.org>

    Fix compilation on TERMINFO platforms with GCC 10
    
    * src/terminfo.c [TERMINFO]: Don't redefine UP, BC, and CP, as
    that could cause linking errors due to multiple definitions.
    (Bug#43195)
---
 src/terminfo.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/terminfo.c b/src/terminfo.c
index 51fd32e..0765996 100644
--- a/src/terminfo.c
+++ b/src/terminfo.c
@@ -23,9 +23,12 @@ along with GNU Emacs.  If not, see 
<https://www.gnu.org/licenses/>.  */
 
 /* Define these variables that serve as global parameters to termcap,
    so that we do not need to conditionalize the places in Emacs
-   that set them.  */
+   that set them.  But don't do that for terminfo, as that could
+   cause link errors when using -fno-common.  */
 
+#if !TERMINFO
 char *UP, *BC, PC;
+#endif
 
 /* Interface to curses/terminfo library.
    Turns out that all of the terminfo-level routines look