Pass name of file being analyzed to find_by_heuristics

Some languages are sensitive to file names in the sense that
different kinds of files contain somewhat different data.
Example: GAP .tst files contain test cases, which add some
extra data compared to regular code, and as a consequence are
not directly interchangeable with regular source code.

Heuristics may need to take this into account, thus may need
to know the name of the file being analyzed.

lib/linguist/heuristics.rb

@@ -7,11 +7,12 @@ module Linguist
     # apply heuristics against the given data and return an array
     # of matching languages, or nil.
     #
+    # name      - Name of the file the data is coming from.
     # data      - Array of tokens or String data to analyze.
     # languages - Array of language name Strings to restrict to.
     #
     # Returns an array of Languages or []
-    def self.find_by_heuristics(data, languages)
+    def self.find_by_heuristics(name, data, languages)
       if active?
         result = []
 

lib/linguist/language.rb

@@ -120,7 +120,7 @@ module Linguist
       if possible_languages.length > 1
         data = blob.data
         possible_language_names = possible_languages.map(&:name)
-        heuristic_languages = Heuristics.find_by_heuristics(data, possible_language_names)
+        heuristic_languages = Heuristics.find_by_heuristics(name, data, possible_language_names)
 
         if heuristic_languages.size > 1
           possible_language_names = heuristic_languages.map(&:name)