Fix Backtrace view on what frames it considers "interesting"

What is coming from 'NQPCORE.setting' and 'BOOTSTRAP/v6?' is now
considered part of the setting. The former fixes uses of `NQPLock`.
The latter – frames from withing dispatchers, for example.

Don't stop building trace when any `NQP::` file is encountered. Relying
on the prefix alone was causing frames, following calls to
`NQPLock.protect` in the trace, to be skipped until (if we are lucky) a
`SETTING::` prefix found. This fix (and I hope this is a fix, not a
regression) makes the trace to skip only frames after method `eval` in
`NQPHLL/Compiler.nqp`.

src/core.c/Backtrace.rakumod

@@ -65,7 +65,10 @@ my class Backtrace::Frame {
           || $!file ~~ / "CORE." \w+ ".setting" $ /
 #?endif
 #?if !jvm
-          || $!file ~~ / "CORE." \w+ ".setting.{ Rakudo::Internals.PRECOMP-EXT }" $ /
+          || $!file ~~ / [ "CORE." \w+ ".setting"
+                           | "NQPCORE.setting"
+                           | "BOOTSTRAP/v6" \w ]
+                         ".{ Rakudo::Internals.PRECOMP-EXT }" $ /
 #?endif
           || $!file.ends-with(".nqp")
     }
@@ -171,9 +174,11 @@ my class Backtrace {
             next if $file.ends-with('BOOTSTRAP.nqp')
                  || $file.ends-with('QRegex.nqp')
                  || $file.ends-with('Perl6/Ops.nqp');
-            if $file.ends-with('NQPHLL.nqp')
+
+            my $name := nqp::p6box_s(nqp::getcodename($do));
+
+            if ($file.starts-with('NQP::') && $file.ends-with('Compiler.nqp') && $name eq 'eval')
                 || $file.ends-with('NQPHLL.moarvm')
-                || $file.starts-with('NQP::')
             {
                 # This could mean we're at the end of the interesting backtrace,
                 # or it could mean that we're in something like sprintf (which
@@ -195,7 +200,6 @@ my class Backtrace {
             my $line := $annotations<line>;
             next unless $line;
 
-            my $name := nqp::p6box_s(nqp::getcodename($do));
             if $name eq 'handle-begin-time-exceptions' {
                 $!bt-next = $elems;
                 last;