Try this:

use strict;

undef $/;#In order to read the whole file at once
open(F,"test.txt") or die $!;
my $slurpedfile = <F>;
close F;
my @matches =  $slurpedfile =~
m{
     ( /\* .*? \*/) | ( \/\/[^\n]*)
     | " (?: [^"\\]* | \\. )* "
     | ' (?: [^'\\]* | \\. )* '
     | . [^/"']*
   }xgs;

@matches = grep {defined $_} @matches; #get rid of undefs
my $linenum = 1;

foreach my $match (@matches) {

        $slurpedfile =~ /\Q$match/;
        my $before = $`;
        $slurpedfile = $';
        $linenum += $before =~ tr/\n/\n/;

        foreach (split "\n", $match) {
            print "Line $linenum\t$_\n";
            $linenum++;
        }
        $linenum--;  # the foreach above adds one too many
}

__OUTPUT__
Line 2  //Hello
Line 3  // single line c++ comment
Line 5  /* single line c comment */
Line 6  /*
Line 7      multi line
Line 8      c style comment */
Line 10 // another single line c++ comment
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--

flounder