Fix regex in ClassifyFiles.

`Comment.getText()` does not include the delimiter.

ql/src/filters/ClassifyFiles.ql

@@ -15,9 +15,7 @@ string generatorCommentRegex() {
   result = "This (file|class|interface|art[ei]fact) (was|is) (?:mechanically|automatically) generated" or
   result = "The following code was (?:auto[ -]?)?generated (?:by|from)" or
   result = "Autogenerated by Thrift" or
-  result = "(Code g|G)enerated from .* by ANTLR" or
-  // regular expression recommended for Go code generators (https://golang.org/pkg/cmd/go/internal/generate/)
-  result = "(^|\n)// Code generated .* DO NOT EDIT\\.($|\n)"
+  result = "(Code g|G)enerated from .* by ANTLR"
 }
 
 predicate classify(File f, string category) {
@@ -36,6 +34,10 @@ predicate classify(File f, string category) {
   // generated code
   exists(Comment c | c.getFile() = f |
     c.getText().regexpMatch("(?i).*\\b(" + concat(generatorCommentRegex(), "|") + ")\\b.*")
+    or
+    // regular expression recommended for Go code generators
+    // (https://golang.org/pkg/cmd/go/internal/generate/)
+    c.getText().regexpMatch("^\\s*Code generated .* DO NOT EDIT\\.\\s*$")
   ) and
   category = "generated"
 }

ql/test/query-tests/filters/ClassifyFiles/ClassifyFiles.expected

@@ -1 +1,2 @@
+| hello2.go:0:0:0:0 | hello2.go | generated |
 | hello.go:0:0:0:0 | hello.go | generated |

ql/test/query-tests/filters/ClassifyFiles/hello2.go

@@ -0,0 +1,9 @@
+// Code generated from stuff; DO NOT EDIT.
+
+package main
+
+import "fmt"
+
+func main2() {
+	fmt.Println("Hello, world!")
+}