stdlib/lists: Add function droplast/1
This functions drops the last element of a non-empty list.

lists:last/1 and lists:droplast/1 are the dual of hd/1 and tl/1 but
for the end of a list.
Added tests for lists:droplast/1 to stdlib/lists_SUITE
Added documentation of lists:droplast/1
Import and use lists:droplast/1 in v3_core/v3_kernel

Also imported lists:last/1, and removed the local definition.
Use lists:droplast/1 in orber/orber_interceptors.erl
lib/wx - Replace reverse(tl(reverse(L))) with lists:droplast/1
lib/ssh - Replace reverse(tl(reverse(L))) with lists:droplast/1
Support named funs in erl_prettypr
Don't munge record and field names in cover

They are bare atoms, atoms or variables in the abstract format, there is no need to
pass them through munge_expr/2.
Properly munge record updates in cover

Trees {record,Line,Arg,Name,Fields} were not munged.
lib/mnesia/test/ - Replace reverse(tl(reverse(L))) with lists:droplast/1
remove unused parameter
remove useless match
remove warning for variable exported from case
erts: Fix Maps for beam_load

Map source may be anything, not only registers.
erts: Maps must fail on exact updates of empty Maps

Exact updates on empty Maps must fail directly.
compiler: Update map_SUITE with error case test

  M#{ key := V } should fail when M is not a Map
Merge branch 'egil/erts/fix-maps-beam_load'

* egil/erts/fix-maps-beam_load:
  compiler: Update map_SUITE with error case test
  erts: Maps must fail on exact updates of empty Maps
  erts: Fix Maps for beam_load
Merge branch 'hsv/add_droplast_to_lists'

* hsv/add_droplast_to_lists:
  Added documentation of lists:droplast/1
  Added tests for lists:droplast/1 to stdlib/lists_SUITE
  stdlib/lists: Add function droplast/1 This functions drops the last element of a non-empty list.
Merge branch 'hsv/using_lists_droplast'

* hsv/using_lists_droplast:
  lib/mnesia/test/ - Replace reverse(tl(reverse(L))) with lists:droplast/1
  lib/ssh - Replace reverse(tl(reverse(L))) with lists:droplast/1
  lib/wx - Replace reverse(tl(reverse(L))) with lists:droplast/1
  Use lists:droplast/1 in orber/orber_interceptors.erl
  Import and use lists:droplast/1 in v3_core/v3_kernel

OTP-11678
OTP-11677