+ * new feature: SB-EXT:DEFGLOBAL macro allows defining global non-special
+ variables.
+ * new feature: SB-EXT:ALWAYS-BOUND proclamation inhibits MAKUNBOUND, and
+ allows the compiler to safely elide boundedness checks for special
+ variables.
+ * new feature: SB-EXT:GLOBAL proclamation inhibits SPECIAL proclamations for
+ the symbol, prohibits both lexical and dynamic binding. This is mainly an
+ efficiency measure for threaded platforms, but also valueable in
+ expressing intent.
+ * improvement: SBCL now emits a compiler note where stack allocation was
+ requested but could not be provided.