Fix #79650: php-win.exe 100% cpu lockup

As of PHP 7.3.0, `sapi_cli_single_write()` is supposed to return `< 0`
on failure, but `fwrite()` returns a `size_t`, and signals error by
setting the stream's error indicator.  We have to cater to that.

Author: cmb69

NEWS

@@ -2,6 +2,8 @@ PHP                                                                        NEWS
 |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
 ?? ??? ????, PHP 7.3.20
 
+- Core:
+  . Fixed bug #79650 (php-win.exe 100% cpu lockup). (cmb)
 
 ?? ??? ????, PHP 7.3.19
 

sapi/cli/php_cli.c

@@ -279,6 +279,9 @@ PHP_CLI_API ssize_t sapi_cli_single_write(const char *str, size_t str_length) /*
 	} while (ret <= 0 && errno == EAGAIN && sapi_cli_select(STDOUT_FILENO));
 #else
 	ret = fwrite(str, 1, MIN(str_length, 16384), stdout);
+	if (ret == 0 && ferror(stdout)) {
+		return -1;
+	}
 #endif
 	return ret;
 }