[GR-24682] Minor fixes: use uinon merge for some files, bump serialization version, fix args parsing in graalpytest.

PullRequest: graalpython/1175

Author: steve-s

.gitattributes

@@ -0,0 +1,2 @@
+CHANGELOG.md merge=union
+graalpython/com.oracle.graal.python/src/com/oracle/graal/python/nodes/ErrorMessages.java merge=union

graalpython/com.oracle.graal.python.test/src/graalpytest.py

@@ -705,7 +705,8 @@ class TextTestResult():
                 patterns.append(argv.pop(idx))
             except IndexError:
                 print("-k needs an argument")
-        idx += 1
+        else:
+            idx += 1
 
     if argv[1] == "-v":
         verbose = True

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/parser/sst/SerializationUtils.java

@@ -45,7 +45,7 @@
 import com.oracle.graal.python.nodes.expression.UnaryArithmetic;
 
 public class SerializationUtils {
-    public static byte VERSION = 3;
+    public static byte VERSION = 4;
 
     public static enum SSTId {
         AndID,