patch 9.1.0946: cross-compiling fails on osx-arm64

Problem:  cross-compiling fails on osx-arm64
Solution: use vim_cv_timer_create_with_lrt() instead of
          vim_cv_timer_create_works() (Brandon Maier)

Cross-compiling to osx-arm64 fails with the following

  In file included from json.c:17:
  In file included from ./vim.h:457:
  ./macros.h:304:24: error: expected identifier or '('
    304 |      static inline int isnan(double x)
        |                        ^
  .../MacOSX11.0.sdk/usr/include/math.h:165:7: note: expanded from macro 'isnan'
    165 |     ( sizeof(x) == sizeof(float)  ? __inline_isnanf((float)(x))
        |       ^

This can be traced back to ./configure incorrectly detecting the
compiler support for `isnan()`, from the config.log:

  configure:14567: checking for isnan()
  configure:14588: arm64-apple-darwin20.0.0-clang <...> -L$PREFIX/lib conftest.c  -lncurses -ltinfo -lrt >&5
  ld: library not found for -lrt
  arm64-apple-darwin20.0: error: linker command failed with exit code 1 (use -v to see invocation)

The `-lrt` linking is added by ./configure script when it detects
compiler support for `timer_create()`. On the osx-arm64 platform
`timer_create()` works but does not link with `-lrt`. This results in
the following settings from config.log:

  vim_cv_timer_create=yes
  vim_cv_timer_create_with_lrt=no
  vim_cv_timer_create_works=yes

But the configure.ac incorrectly uses `timer_create_works` to add
`-lrt`, instead of using `timer_create_with_lrt`.

fixes: https://github.com/conda-forge/vim-feedstock/pull/1664
closes: #16242

Signed-off-by: Brandon Maier <brandon.maier@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/auto/configure b/src/auto/configure
index 062119e..2c9d9e8 100755
--- a/src/auto/configure
+++ b/src/auto/configure
@@ -14234,7 +14234,7 @@
 if test "x$vim_cv_timer_create" = "xyes" ||
    test "x$vim_cv_timer_create_with_lrt" = "xyes"; then
   save_LIBS="$LIBS"
-  if test "x$vim_cv_timer_create_works" = "xyes" ; then
+  if test "x$vim_cv_timer_create_with_lrt" = "xyes" ; then
     LIBS="$LIBS -lrt"
   fi
 
@@ -14297,7 +14297,6 @@
   if test "x$vim_cv_timer_create_works" = "xyes" ; then
     printf "%s\n" "#define HAVE_TIMER_CREATE 1" >>confdefs.h
 
-    LIBS="$LIBS -lrt"
   else
     LIBS="$save_LIBS"
   fi
diff --git a/src/configure.ac b/src/configure.ac
index 56895f6..2943ec5 100644
--- a/src/configure.ac
+++ b/src/configure.ac
@@ -3908,7 +3908,7 @@
 if test "x$vim_cv_timer_create" = "xyes" ||
    test "x$vim_cv_timer_create_with_lrt" = "xyes"; then
   save_LIBS="$LIBS"
-  if test "x$vim_cv_timer_create_works" = "xyes" ; then
+  if test "x$vim_cv_timer_create_with_lrt" = "xyes" ; then
     LIBS="$LIBS -lrt"
   fi
 
@@ -3939,7 +3939,6 @@
 
   if test "x$vim_cv_timer_create_works" = "xyes" ; then
     AC_DEFINE(HAVE_TIMER_CREATE)
-    LIBS="$LIBS -lrt"
   else
     LIBS="$save_LIBS"
   fi