Renaming glpk-4.54.ebuild to glpk-4.55.ebuild works without problems. The patch still applies perfectly and the library version is 36.1.2 as opposed to 36.1.1 in 4.54. So the slot 0/36 is still valid.
Has there been any progress on this? Upstream has had it since September 2014.
+*glpk-4.55 (27 Feb 2015) + + 27 Feb 2015; Justin Lecher <jlec@gentoo.org> +glpk-4.55.ebuild, + glpk-4.45.ebuild, glpk-4.48.ebuild, metadata.xml: + Version BUmp, #532906; fix missing slot Operators and inherits +