mingw: add x86_64-linux-glibc2.15-4.8 gcc prebuilt

Bug: b/73539603
Test: ./toolchain/mingw/build.sh (after updating script)
Change-Id: Ia0f59c3358b9be736fbacb13ebd9ee42a38fd2dc
1 file changed
tree: 24543217482f2a270ede64cdb441d55b84022de5
  1. default.xml