Dump-parsed-ast fails for very large Fractional number constants

The existing test file T15271.hs has

main = do
  print 1e646457008
  print 1e646457009 -- T15271: This incorrectly printed 0.0
  print 1e1555550000 -- This is still infinity
  print 1e1000000000 -- T15271: This incorrectly printed 0.0

Trying to run ghc --dump-parsed-ast T15271.hs` fails, using up all available memory.

When dumping the file in ghc-exacptrint, the start looks like this

                       ({ tests/examples/ghc88-copied/T15271.hs:2:9-19 }
                        Just (Ann (DP (0,1)) [] [] [((G AnnVal),DP (0,0))] Nothing Nothing)
                        (HsOverLit 
                         (NoExt) 
                         (OverLit 
                          (NoExt) 
                          (HsFractional 
                           (FL 
                            (SourceText "1e646457008") 
                            (False) 
                            (:% 
                             (100000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
.....

I am not sure if this is an actual problem, but it is worth noting.

Trac metadata

Trac field	Value
Version	8.6.3
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
Test case
Differential revisions
BlockedBy
Related
Blocking
CC
Operating system
Architecture