Clean up errors due to gcc's -Werror=unused-but-set-variable
Clean up errors due to gcc's -Werror=unused-but-set-variable

Newer gcc's (>4.6?) produced warnings due to variables that were set
but unused.  All but one of the cases were for variables used in LLVM
back end compilation, so those were simply #ifdef'ed out for standard
compilation.  The other looks like it was accidentally committed in
r20554 (bulk comm merge from branch).  I'm assuming this was
accidentally left over crud.



git-svn-id: 88467cb1fb04b8a755be7e1ee1026be4190196ef@20644 3a8e244f-b0f2-452b-bcba-4c88e055c3ca

hildeth/chapel,sungeunchoi/chapel,sungeunchoi/chapel,CoryMcCartan/chapel,hildeth/chapel,CoryMcCartan/chapel,hildeth/chapel,chizarlicious/chapel,CoryMcCartan/chapel,chizarlicious/chapel,hildeth/chapel,sungeunchoi/chapel,CoryMcCartan/chapel,chizarlicious/chapel,chizarlicious/chapel,chizarlicious/chapel,CoryMcCartan/chapel,sungeunchoi/chapel,chizarlicious/chapel,hildeth/chapel,hildeth/chapel,CoryMcCartan/chapel,sungeunchoi/chapel,hildeth/chapel,CoryMcCartan/chapel,sungeunchoi/chapel,chizarlicious/chapel,sungeunchoi/chapel,sungeunchoi/chapel