Hide unbase/unbase_bracket by uppercasing them

Since these are leaked to the PROCESS:: namespace, and not documented in the
spec, we should probably hide them by obscurity for now.

src/Perl6/Actions.nqp

@@ -5607,11 +5607,11 @@ class Perl6::Actions is HLL::Actions does STDActions {
     method rad_number($/) {
         my $radix    := +($<radix>.Str);
         if $<bracket>   {
-            make QAST::Op.new(:name('&unbase_bracket'), :op('call'),
+            make QAST::Op.new(:name('&UNBASE_BRACKET'), :op('call'),
                 $*W.add_numeric_constant($/, 'Int', $radix), $<bracket>.ast);
         }
         elsif $<circumfix> {
-            make QAST::Op.new(:name('&unbase'), :op('call'),
+            make QAST::Op.new(:name('&UNBASE'), :op('call'),
                 $*W.add_numeric_constant($/, 'Int', $radix), $<circumfix>.ast);
         } else {
             my $intpart  := $<intpart>.Str;

src/core/Str.pm

@@ -1382,11 +1382,11 @@ sub trim-leading (Str:D $s) returns Str:D { $s.trim-leading }
 sub trim-trailing(Str:D $s) returns Str:D { $s.trim-trailing }
 
 # the opposite of Real.base, used for :16($hex_str)
-proto sub unbase (|) { * }
-multi sub unbase(Int:D $base, Cool:D $num) is hidden_from_backtrace {
+proto sub UNBASE (|) { * }
+multi sub UNBASE(Int:D $base, Cool:D $num) is hidden_from_backtrace {
     X::Numeric::Confused.new(:what($num)).throw;
 }
-multi sub unbase(Int:D $base, Str:D $str) is hidden_from_backtrace {
+multi sub UNBASE(Int:D $base, Str:D $str) is hidden_from_backtrace {
     my Str $prefix = $str.substr(0, 2);
     if    $base <= 10 && $prefix eq any(<0x 0d 0o 0b>)
        or $base <= 24 && $prefix eq any <0o 0x>
@@ -1399,7 +1399,7 @@ multi sub unbase(Int:D $base, Str:D $str) is hidden_from_backtrace {
 }
 
 # for :16[1, 2, 3]
-sub unbase_bracket($base, @a) is hidden_from_backtrace {
+sub UNBASE_BRACKET($base, @a) is hidden_from_backtrace {
     my $v = 0;
     my $denom = 1;
     my Bool $seen-dot = False;