Make 'likely' macro available in all of Emacs (bug#81115)

* src/android.c (likely): Move ...
* src/conf_post.h (likely): ... here.  Ensure true values which aren't
equal to 1 are still predicted correctly.

src/android.c

@@ -6158,8 +6158,6 @@ android_build_jstring (const char *text)
    if global_foo cannot be allocated, and after the global reference
    is created.  */
 
-#define likely(cond)	__builtin_expect (cond, 1)
-
 /* Check for JNI exceptions and call memory_full in that
    situation.  */
 

src/conf_post.h

@@ -371,6 +371,11 @@ extern int emacs_setenv_TZ (char const *);
 # define UNINIT /* empty */
 #endif
 
+/* likely (COND) is equivalent to COND ? 1 : 0, but instructs the
+   compiler to provide static branch prediction hints to the CPU so that
+   the branch isn't mispredicted.  */
+#define likely(cond)	__builtin_expect (!!(cond), 1)
+
 /* Emacs needs neither glibc strftime behavior for AM and PM indicators,
    nor Gnulib strftime support for non-Gregorian calendars.  */
 #define REQUIRE_GNUISH_STRFTIME_AM_PM false