For PR1099:

Invert the "isSigned" logic in calls to printType and printPrimitiveType.
We want variables to be declared unsigned by default so that signless
operators like + and - perform the unsigned operation that LLVM expects
by default. Parameters with the sext attribute will be declared signed and
signed instructions will case operand values to signed regardless of the
type of the variable. This passes all tests and fixes PR1099.

llvm-svn: 33039