Update SEEC_PP_COUNT_VA to expand to zero when __VA_ARGS__ is empty.

Update SEEC_PP_APPLY to expand to nothing when __VA_ARGS__ is empty.
Include <cstdint> for uint64_t.
Add ClangEPV descriptions for ArraySubscriptExpr, BreakStmt, CallExpr, and
DoStmt.

Add formatAsInt() for int32_t and int64_t types.