main/cgdb: fix build on mips* (name collision)

There is a variable called "mips" in the code that conflicts with the
predefined "mips" macro. Add -std=c11 / -std=c++11 to CFLAGS / CXXFLAGS
to force removal of all the non-underscored predefined macros. This is
safe because README.md says the project is officially C11/C++11.

main/cgdb/APKBUILD

@@ -2,7 +2,7 @@
 # Maintainer: Natanael Copa <ncopa@alpinelinux.org>
 pkgname=cgdb
 pkgver=0.7.0
-pkgrel=1
+pkgrel=2
 pkgdesc="The Curses Debugger"
 arch="all"
 license="GPL-2.0"
@@ -15,6 +15,8 @@ builddir="$srcdir/$pkgname-$pkgver"
 
 build() {
 	cd "$builddir"
+	CFLAGS="$CFLAGS -std=c11" \
+	CXXFLAGS="$CXXFLAGS -std=c++11" \
 	./configure \
 		--build=$CBUILD \
 		--host=$CHOST \