testsuite: Bump allocations for T1969 and T5837
testsuite: Bump allocations for T1969 and T5837

Sadly it's not immediately obvious where this regression came from:

 * T5837 started failing on OS X with 0c2350c293b82e4cb24a66e00b904933bdb1c8f3
 * It's not clear when T1969 started failing due to the recent out of memory
   issues on Harbormaster

sdiehl/ghc,sdiehl/ghc,sdiehl/ghc,sdiehl/ghc,sdiehl/ghc,sdiehl/ghc,sdiehl/ghc