mips32/mips64: Fix compiler warnings.

Fix some compiler warnings when compiling Valgrind for mips32/mips64.
Clean up exp files for mips32 BE and LE.


git-svn-id: svn://svn.valgrind.org/valgrind/trunk@13496 a5019735-40e9-0310-863c-91ae7b9d1cf9
mips32: Delete unnecessary exp files.


git-svn-id: svn://svn.valgrind.org/valgrind/trunk@13497 a5019735-40e9-0310-863c-91ae7b9d1cf9
Followup to VEX r2742 which eliminates IRExprP__VECRET and IRExprP__BBPTR
and adds Iex_VECRET and Iex_BBPTR.


git-svn-id: svn://svn.valgrind.org/valgrind/trunk@13498 a5019735-40e9-0310-863c-91ae7b9d1cf9