Merge branch 'PHP-7.1' into PHP-7.2

* PHP-7.1:
  minor loop optimizations, closes #2633

diff --cc ext/mysqli/mysqli.c
Simple merge

diff --cc ext/mysqli/mysqli_api.c
Simple merge

diff --cc win32/sendmail.c
index c71ab2201faaa1df5858bf51d53f387daad6c0ef,808fc8f5fd34e7e1777d56788ddb206fcc2d1f43..62d710589de968284001ff7f9a5d718ce91c2014
--- 1/win32/sendmail.c
--- 2/win32/sendmail.c
+++ b/win32/sendmail.c
@@@ -677,8 -698,15 +677,12 @@@ static int PostHeader(char *RPath, cha
        size_t i;
  
        if (xheaders) {
 -              if (NULL == (headers_lc = estrdup(xheaders))) {
 -                      return OUT_OF_MEMORY;
 -              }
 -
+               size_t headers_lc_len;
+ 
-               for (i = 0; i < strlen(headers_lc); i++) {
 +              headers_lc = estrdup(xheaders);
+               headers_lc_len = strlen(headers_lc);
+ 
+               for (i = 0; i < headers_lc_len; i++) {
                        headers_lc[i] = tolower(headers_lc[i]);
                }
        }