glibc: Add --enable-obsolete-rpc
glibc: Add --enable-obsolete-rpc

Closes Linuxbrew/linuxbrew#603.
Closes Linuxbrew/linuxbrew#766.

Signed-off-by: Shaun Jackman <b580dab3251a9622aba3803114310c23fdb42900@gmail.com>

saketkc/linuxbrew,Angeldude/linuxbrew,Linuxbrew/linuxbrew,drbenmorgan/linuxbrew,ebouaziz/linuxbrew,Homebrew/linuxbrew,reelsense/linuxbrew,gnubila-france/linuxbrew,reelsense/linuxbrew,reelsense/linuxbrew,Homebrew/linuxbrew,Linuxbrew/linuxbrew,Angeldude/linuxbrew,drbenmorgan/linuxbrew,sjackman/linuxbrew,saketkc/linuxbrew,SuperNEMO-DBD/cadfaelbrew,Linuxbrew/linuxbrew,SuperNEMO-DBD/cadfaelbrew,bukzor/linuxbrew,SuperNEMO-DBD/cadfaelbrew,gnubila-france/linuxbrew,sjackman/linuxbrew,drbenmorgan/linuxbrew,bukzor/linuxbrew,ebouaziz/linuxbrew,drbenmorgan/linuxbrew,bukzor/linuxbrew,bukzor/linuxbrew,DoomHammer/linuxbrew,saketkc/linuxbrew,Angeldude/linuxbrew,sjackman/linuxbrew,Homebrew/linuxbrew,ebouaziz/linuxbrew,Homebrew/linuxbrew,Angeldude/linuxbrew,saketkc/linuxbrew,SuperNEMO-DBD/cadfaelbrew,sjackman/linuxbrew,DoomHammer/linuxbrew,gnubila-france/linuxbrew,DoomHammer/linuxbrew,Linuxbrew/linuxbrew,ebouaziz/linuxbrew,DoomHammer/linuxbrew,gnubila-france/linuxbrew,reelsense/linuxbrew