Merge pull request #659 from resetnow/master

Add C11 flag support for GCC

src/_premake_init.lua

@@ -505,6 +505,7 @@
 			"C++14",
 			"C90",
 			"C99",
+			"C11",
 		},
 		aliases = {
 			FatalWarnings = { "FatalWarnings", "FatalCompileWarnings", "FatalLinkWarnings" },

src/tools/gcc.lua

@@ -89,6 +89,7 @@
 		flags = {
 			["C90"] = "-std=gnu90",
 			["C99"] = "-std=gnu99",
+			["C11"] = "-std=gnu11",
 		},
 	}