Use ArrayElement accessor where needed

Author: smowton

java/ql/src/semmle/code/java/frameworks/apache/Lang.qll

@@ -644,11 +644,13 @@ private class ApacheToStringBuilderModel extends SummaryModelCsv {
       [
         "org.apache.commons.lang3.builder;ToStringBuilder;false;toString;;;Argument[-1];ReturnValue;taint",
         "org.apache.commons.lang3.builder;ToStringBuilder;false;append;(java.lang.Object);;Argument[0];Argument[-1];taint",
-        "org.apache.commons.lang3.builder;ToStringBuilder;false;append;(java.lang.Object[]);;Argument[0];Argument[-1];taint",
-        "org.apache.commons.lang3.builder;ToStringBuilder;false;append;(java.lang.String,java.lang.Object[]);;Argument[0..1];Argument[-1];taint",
+        "org.apache.commons.lang3.builder;ToStringBuilder;false;append;(java.lang.Object[]);;ArrayElement of Argument[0];Argument[-1];taint",
+        "org.apache.commons.lang3.builder;ToStringBuilder;false;append;(java.lang.String,java.lang.Object[]);;Argument[0];Argument[-1];taint",
+        "org.apache.commons.lang3.builder;ToStringBuilder;false;append;(java.lang.String,java.lang.Object[]);;ArrayElement of Argument[1];Argument[-1];taint",
         "org.apache.commons.lang3.builder;ToStringBuilder;false;append;(java.lang.String,boolean);;Argument[0];Argument[-1];taint",
         "org.apache.commons.lang3.builder;ToStringBuilder;false;append;(java.lang.String,java.lang.Object);;Argument[0..1];Argument[-1];taint",
-        "org.apache.commons.lang3.builder;ToStringBuilder;false;append;(java.lang.String,java.lang.Object[],boolean);;Argument[0..1];Argument[-1];taint",
+        "org.apache.commons.lang3.builder;ToStringBuilder;false;append;(java.lang.String,java.lang.Object[],boolean);;Argument[0];Argument[-1];taint",
+        "org.apache.commons.lang3.builder;ToStringBuilder;false;append;(java.lang.String,java.lang.Object[],boolean);;ArrayElement of Argument[1];Argument[-1];taint",
         "org.apache.commons.lang3.builder;ToStringBuilder;false;build;;;Argument[-1];ReturnValue;taint",
         "org.apache.commons.lang3.builder;ToStringBuilder;false;getStringBuffer;;;Argument[-1];ReturnValue;taint",
         "org.apache.commons.lang3.builder;ToStringBuilder;false;appendToString;;;Argument[0];Argument[-1];taint",