Fix compilation of \n on JVM

Author: sorear

src/vm/jvm/QAST/Compiler.nqp

@@ -4440,21 +4440,12 @@ class QAST::CompilerJAST {
             $il.append($L2I);
             $il.append(JAST::Instruction.new( :op($node.negate ?? 'ifne' !! 'ifeq'), %*REG<fail> ));
 
-            if $subtype == nqp::const::CCLASS_NEWLINE {
+            if $cclass == nqp::const::CCLASS_NEWLINE && !$node.negate {
                 $il.append(JAST::Instruction.new( :op('aload'), %*REG<tgt> ));
                 $il.append(JAST::Instruction.new( :op('lload'), %*REG<pos> ));
-                $il.append($L2I);
-                $il.append($DUP);
-                $il.append(JAST::PushIndex.new( :value(2) ));
-                $il.append($IADD);
-                $il.append(JAST::Instruction.new( :op('invokevirtual'),
-                    $TYPE_STR, 'substring', $TYPE_STR, 'Integer', 'Integer' ));
-                $il.append(JAST::PushSVal.new( :value("\r\n") ));
-                $il.append(JAST::Instruction.new( :op('invokevirtual'),
-                    $TYPE_STR, 'equals', 'Z', $TYPE_OBJ ));
-                $il.append($I2L);
-                $il.append(JAST::Instruction.new( :op('lload'), %*REG<pos> ));
-                $il.append($LADD);
+                $il.append(JAST::Instruction.new( :op('lload'), %*REG<eos> ));
+                $il.append(JAST::Instruction.new( :op('invokestatic'),
+                    $TYPE_OPS, 'checkcrlf', 'Long', $TYPE_STR, 'Long', 'Long' ));
                 $il.append(JAST::Instruction.new( :op('lstore'), %*REG<pos> ));
             } 
         }

src/vm/jvm/runtime/org/perl6/nqp/runtime/Ops.java

@@ -2643,7 +2643,11 @@ public static long iscclass(long cclass, String target, long offset) {
             return 0;
         }
     }
-    
+
+    public static long checkcrlf(String tgt, long pos, long eos) {
+        return (pos <= eos-2 && tgt.substring((int)pos, ((int) pos)+2).equals("\r\n")) ? pos+1 : pos;
+    }
+
     public static long findcclass(long cclass, String target, long offset, long count) {
         long length = target.length();
         long end = offset + count;