Parser rejects valid block argument syntax in Resource::Silo

[fglock]

Summary

PerlOnJava rejects valid Perl syntax used by Resource::Silo 0.1703. The
failure occurs while compiling the module, before its tests can run.

Reproduction

This standard-Perl expression is accepted by Perl 5:

my $shortcut_sub = set_prototype {
    $instance //= $target->new;
} '';

PerlOnJava reports a syntax error at the closing expression. The smallest
reproducer is:

use Scalar::Util qw(set_prototype);
my $x = set_prototype { 1 } q{};

Evidence

• Distribution: Resource-Silo 0.1703
• CPAN random tester run: 20260922-180448-60378
• Failing test: t/001-load.t, during use Resource::Silo
• System Perl: PASS, 39 test files and 148 tests
• PerlOnJava JVM backend: FAIL
• PerlOnJava interpreter backend: FAIL
• The minimal reproducer passes on system Perl and fails on both PerlOnJava
  backends.
• The distribution is pure Perl and does not require XS or native code.

Expected behavior

PerlOnJava should parse and execute a function call whose first argument is an
anonymous block followed by a second expression, matching standard Perl's
handling of set_prototype { ... } ''.

Acceptance criteria

• Add focused project-owned regression coverage for this syntax.
• The regression passes on both JVM and interpreter backends.
• Resource-Silo 0.1703 passes its complete upstream test suite.