Fixes/improvements to IO::Socket::INET.get.

* Bring API in line with IO::Handle, using nl-in for the input
  separator and allowing multiple separators
* Make default separators CR and CRLF, like other handles (this fixes
  the recent Panda regression)
* Use VM-backed chomped line reading, and remove custom logic for it.

src/core/IO/Socket/INET.pm

@@ -25,8 +25,8 @@ my class IO::Socket::INET does IO::Socket {
     has $.family = PIO::PF_INET;
     has $.proto = PIO::PROTO_TCP;
     has $.type = PIO::SOCK_STREAM;
-    has Str $.input-line-separator is rw = "\x0A";
-    has Int $.ins = 0;
+    has $.nl-in is rw = ["\x0A", "\r\n"];
+    has int $.ins;
 
     my sub v4-split($uri) {
         return $uri.split(':', 2);
@@ -85,34 +85,34 @@ my class IO::Socket::INET does IO::Socket {
         self;
     }
 
+    method input-line-separator is rw {
+        DEPRECATED('nl-in');
+        self.nl-in
+    }
+
     method get() {
-        my Mu $io       := nqp::getattr(self, $?CLASS, '$!PIO');
-        my str $encoding = Rakudo::Internals.NORMALIZE_ENCODING($!encoding);
-        nqp::setencoding($io, $encoding);
-        my str $sep = nqp::unbox_s($!input-line-separator);
-        nqp::setinputlinesep($io, $sep);
-        my int $sep-len = nqp::chars($sep);
-        my str $line    = nqp::readlinefh($io);
-        my int $len     = nqp::chars($line);
-
-        if $len == 0 { Str }
+        my Mu $io := nqp::getattr(self, $?CLASS, '$!PIO');
+        nqp::setencoding($io, Rakudo::Internals.NORMALIZE_ENCODING($!encoding));
+        Rakudo::Internals.SET_LINE_ENDING_ON_HANDLE($io, $!nl-in);
+        my str $line = nqp::readlinechompfh($io);
+        if nqp::chars($line) || !nqp::eoffh($io) {
+            $!ins = $!ins + 1;
+            $line
+        }
         else {
-            ++$!ins;
-            $len >= $sep-len && nqp::eqat($line, $sep, $len - $sep-len)
-                ?? nqp::p6box_s(nqp::substr($line, 0, $len - $sep-len))
-                !! nqp::p6box_s($line);
+            Str
         }
     }
 
     method lines() {
-        gather while (my $line = self.get()).defined {
+        gather while (my $line = self.get()).DEFINITE {
             take $line;
         }
     }
 
     method accept() {
         ## A solution as proposed by moritz
-        my $new_sock := $?CLASS.bless(:$!family, :$!proto, :$!type, :$!input-line-separator);
+        my $new_sock := $?CLASS.bless(:$!family, :$!proto, :$!type, :$!nl-in);
 #?if jvm
         nqp::getattr($new_sock, $?CLASS, '$!buffer') = buf8.new;
 #?endif