[perl #131389] Some parsing glitch with `\term` in a string

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# New Ticket Created by  Zoffix Znet 
# Please include the string:  [perl #131389]
# in the subject line of all future correspondence about this issue. 
# <URL: https://rt.perl.org/Ticket/Display.html?id=131389 >


IRC: https://irclog.perlgeek.de/perl6-dev/2017-05-28#i_14648548

The first eval uses emoji cat in a string and it works;
The second one tries to do the same in a bit more elaborate eval and it crashes 
with bogus term error;
The third one executes the same code, except swapping \term:<😹> to \x, and it 
works fine;
The fourth one executes the same code, except swapping \term:<😹> to \term:<x>, 
and now it crashes with "undeclared routine x";
The last one uses \term:<x>, except it works fine.

Seems in the problematic cases, the defined \term is not seen by the block 
inside the string.


09:07   Zoffix  m: my \term:<😹> = -42; say 😹; say 😹.abs; say "{😹}"; my $foo = 
''; say "{😹.abs}:$foo" for 😹.abs
09:07   camelia rakudo-moar 87d0e0: OUTPUT: «-42␤42␤-42␤42:␤»
09:07   Zoffix  m:    '/tmp/file1'.IO.spurt: "a\nb\nc"; '/tmp/file2'.IO.spurt: 
"d\ne\n"; '/tmp/file3'.IO.spurt: "f\ng\nh\ni"; my $line; my \term:<😹> = 
IO::CatHandle.new('/tmp/file1', '/tmp/file2'.IO, '/tmp/file3'.IO.open,        
:on-switch{ $line = 1 }); say "{😹.path}:$line $_" for 😹.lines
09:07   camelia rakudo-moar 87d0e0: OUTPUT: «5===SORRY!5=== Error while 
compiling <tmp>␤Bogus statement␤at <tmp>:1␤------> 3        :on-switch{ $line = 
1 }); say "{7⏏5😹.path}:$line $_" for 😹.lines␤    expecting any of:␤        
prefix␤        term␤»
09:07   Zoffix  m:    '/tmp/file1'.IO.spurt: "a\nb\nc"; '/tmp/file2'.IO.spurt: 
"d\ne\n"; '/tmp/file3'.IO.spurt: "f\ng\nh\ni"; my $line; my \x = 
IO::CatHandle.new('/tmp/file1', '/tmp/file2'.IO, '/tmp/file3'.IO.open,        
:on-switch{ $line = 1 }); say "{x.path}:$line $_" for x.lines
09:07   camelia rakudo-moar 87d0e0: OUTPUT: «/tmp/file1:1 a␤/tmp/file1:1 
b␤/tmp/file1:1 c␤/tmp/file2:1 d␤/tmp/file2:1 e␤/tmp/file3:1 f␤/tmp/file3:1 
g␤/tmp/file3:1 h␤/tmp/file3:1 i␤»
09:12           m:    '/tmp/file1'.IO.spurt: "a\nb\nc"; '/tmp/file2'.IO.spurt: 
"d\ne\n"; '/tmp/file3'.IO.spurt: "f\ng\nh\ni"; my $line; my \term:<x> = 
IO::CatHandle.new('/tmp/file1', '/tmp/file2'.IO, '/tmp/file3'.IO.open,        
:on-switch{ $line = 1 }); say "{x.path}:$line $_" for x.lines
09:12   camelia rakudo-moar 87d0e0: OUTPUT: «5===SORRY!5=== Error while 
compiling <tmp>␤Undeclared routine:␤    x used at line 1␤␤»
09:12   Zoffix  m: my \term:<x> = 42; say x.path
09:12   camelia rakudo-moar 87d0e0: OUTPUT: «"42".IO␤»