This patch adds warning option -Wstring-plus-int for C/C++.

gcc/ChangeLog:

2017-06-12  Xi Ruoyao  <ryxi@stu.xidian.edu.cn>

	* c-family/c.opt: New option -Wstring-plus-int.
	* c-family/c-common.c (pointer_int_sum): Checking for
	-Wstring-plus-int.
---
 gcc/c-family/c-common.c | 25 +++++++++++++++++++++++++
 gcc/c-family/c.opt      |  5 +++++
 2 files changed, 30 insertions(+)

-- 
Xi Ruoyao <ryxi@stu.xidian.edu.cn>
School of Aerospace Science and Technology, Xidian University