[cvs-nhc98] Fix long-standing bug in @-patterns.

malcolm: Mon Feb 5 19:35:26 CET 2001 Update of /usr/src/master/nhc/src/compiler98 In directory hinken:/tmp/cvs-serv12913 Modified Files: Case.hs Log Message: Fix long-standing bug in @-patterns. An @-pattern in a CAF (i.e. not in an argument position or lambda) generated incorrect code. Example: main = let s@_ = "hello" in print s expected result "hello", actually gave "".