Revert "Convert Xorm sql-injection sinks to MaD"

This reverts commit 3b2b7d7.

Author: smowton

go/ql/lib/ext/xorm.io.xorm.model.yml

@@ -164,6 +164,28 @@ module Gorm {
 module Xorm {
   /** Gets the package name for Xorm. */
   string packagePath() { result = package(["xorm.io/xorm", "github.com/go-xorm/xorm"], "") }
+
+  /** A model for sinks of XORM. */
+  private class XormSink extends SQL::QueryString::Range {
+    XormSink() {
+      exists(Method meth, string type, string name, int n |
+        meth.hasQualifiedName(Xorm::packagePath(), type, name) and
+        this = meth.getACall().getSyntacticArgument(n) and
+        type = ["Engine", "Session"]
+      |
+        name =
+          [
+            "Query", "Exec", "QueryString", "QueryInterface", "SQL", "Where", "And", "Or", "Alias",
+            "NotIn", "In", "Select", "SetExpr", "OrderBy", "Having", "GroupBy"
+          ] and
+        n = 0
+        or
+        name = ["SumInt", "Sum", "Sums", "SumsInt"] and n = 1
+        or
+        name = "Join" and n = [0, 1, 2]
+      )
+    }
+  }
 }
 
 /**