Revert "Add JE_RUNNABLE() and use it for os_unfair_lock_*() test."

This reverts commit 45f83a2ac6.

JE_RUNNABLE() causes general cross-compilation issues.

configure.ac

@@ -43,17 +43,6 @@ AC_CACHE_CHECK([whether $1 is compilable],
                                [$4=no])])
 ])
 
-dnl JE_RUNNABLE(label, hcode, mcode, rvar)
-AC_DEFUN([JE_RUNNABLE],
-[
-AC_CACHE_CHECK([whether $1 is runnable],
-               [$4],
-               [AC_RUN_IFELSE([AC_LANG_PROGRAM([$2],
-                                               [$3])],
-                              [$4=yes],
-                              [$4=no])])
-])
-
 dnl ============================================================================
 
 CONFIG=`echo ${ac_configure_args} | sed -e 's#'"'"'\([^ ]*\)'"'"'#\1#g'`
@@ -1690,11 +1679,7 @@ fi
 dnl ============================================================================
 dnl Check for os_unfair_lock operations as provided on Darwin.
 
-dnl Run the test program rather than merely compiling so that dyld lazy symbol
-dnl binding doesn't result in a false positive if building with a version of
-dnl XCode (>7) that supports the API on a system that is too old to actually
-dnl implement it (<10.12).
-JE_RUNNABLE([Darwin os_unfair_lock_*()], [
+JE_COMPILABLE([Darwin os_unfair_lock_*()], [
 #include <os/lock.h>
 ], [
 	os_unfair_lock lock = OS_UNFAIR_LOCK_INIT;