Description:
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On uClibc, there is no sys/loadavg.h header file, therefore the usability of sys_getloadavg() function going to be disabled during the configure time.

But, we have a /proc/loadavg on uClibc, which returns the following:

0.03 0.03 0.00 2/322 19121

I would really appreciate a patch to solve this.

Thanks.

Actual result:
--------------
configure:12460: checking for sys/loadavg.h
conftest.c:128:25: fatal error: sys/loadavg.h: No such file or directory
 #include <sys/loadavg.h>
| #include <sys/loadavg.h>
configure:14430: checking for getloadavg
/i-data/bf835951/build/php-7.1.11/conftest.c:210: undefined reference to `getloadavg'
| /* Define getloadavg to an innocuous variant, in case <limits.h> declares getloadavg.
| #define getloadavg innocuous_getloadavg
|     which can conflict with char getloadavg (); below.
| #undef getloadavg
| char getloadavg ();
| #if defined __stub_getloadavg || defined __stub___getloadavg
| return getloadavg ();
ac_cv_func_getloadavg=no
ac_cv_header_sys_loadavg_h=no