[perl #130998] [BUG] meta reduce op fails when argumens involve detached methods

[via RT]

# New Ticket Created by  Zoffix Znet 
# Please include the string:  [perl #130998]
# in the subject line of all future correspondence about this issue. 
# <URL: https://rt.perl.org/Ticket/Display.html?id=130998 >


The parse gives 'Confused...' error with both, detached `.grep` and detached 
`.uc` examples.
In addition, when parentheses are removed, the `.grep` version returns an empty 
list, which
is incorrect, while the `'a' .uc` version correctly returns 'A'

17:16   SmokeMachine    m: say [+] ( ^20 .grep: *.is-prime ) # <- is that a bug?
17:16   camelia         rakudo-moar daa71e: OUTPUT: «5===SORRY!5=== Error while 
compiling <tmp>␤Confused␤at <tmp>:1␤------> 3say [+] ( ^20 .7⏏5grep: *.is-prime 
) # <- is that a bug?␤»
17:16   SmokeMachine    m: say [+] ^20 .grep: *.is-prime # <- is that a bug?
17:16   camelia         rakudo-moar daa71e: OUTPUT: «()␤»

17:18   IOninja         m: say [~] 'a' .uc
17:18   camelia         rakudo-moar daa71e: OUTPUT: «A␤»
17:18   IOninja         m: say [~] ("a" .uc)
17:18   camelia         rakudo-moar daa71e: OUTPUT: «5===SORRY!5=== Error while 
compiling <tmp>␤Confused␤at <tmp>:1␤------> 3say [~] ("a" .7⏏5uc)␤»