Remove "find by regex" CallIndex feature

Being able to find methods and targets by regular expressions
was nice but it's not being used now. Meanwhile, it adds overhead
to the call indexing process.

Also, we should ignore call targets that are Sexps, as all searches
for targets use Symbols and hashing Sexps takes time.

lib/brakeman/call_index.rb

@@ -7,8 +7,6 @@ class Brakeman::CallIndex
   def initialize calls
     @calls_by_method = Hash.new { |h,k| h[k] = [] }
     @calls_by_target = Hash.new { |h,k| h[k] = [] }
-    @methods = Set.new
-    @targets = Set.new
 
     index_calls calls
   end
@@ -72,16 +70,12 @@ class Brakeman::CallIndex
       calls.delete_if do |call|
         from_template call, template_name
       end
-
-      @methods.delete name.to_s if calls.empty?
     end
 
     @calls_by_target.each do |name, calls|
       calls.delete_if do |call|
         from_template call, template_name
       end
-
-      @targets.delete name.to_s if calls.empty?
     end
   end
 
@@ -90,27 +84,24 @@ class Brakeman::CallIndex
       calls.delete_if do |call|
         call[:location][0] == :class and classes.include? call[:location][1]
       end
-
-      @methods.delete name.to_s if calls.empty?
     end
 
     @calls_by_target.each do |name, calls|
       calls.delete_if do |call|
         call[:location][0] == :class and classes.include? call[:location][1]
       end
-
-      @targets.delete name.to_s if calls.empty?
     end
   end
 
   def index_calls calls
     calls.each do |call|
-      @methods << call[:method].to_s
-      @targets << call[:target].to_s if call[:target].is_a? Symbol
       @calls_by_method[call[:method]] << call
+
+      unless call[:target].is_a? Sexp
         @calls_by_target[call[:target]] << call
       end
     end
+  end
 
   private
 
@@ -128,18 +119,6 @@ class Brakeman::CallIndex
   def calls_by_target target
     if target.is_a? Array
       calls_by_targets target
-    elsif target.is_a? Regexp
-      targets = @targets.select do |t|
-        t.match target
-      end
-
-      if targets.empty?
-        []
-      elsif targets.length > 1
-        calls_by_targets targets
-      else
-        @calls_by_target[targets.first]
-      end
     else
       @calls_by_target[target]
     end
@@ -158,18 +137,6 @@ class Brakeman::CallIndex
   def calls_by_method method
     if method.is_a? Array
       calls_by_methods method
-    elsif method.is_a? Regexp
-      methods = @methods.select do |m|
-        m.match method
-      end
-
-      if methods.empty?
-        []
-      elsif methods.length > 1
-        calls_by_methods methods
-      else
-        @calls_by_method[methods.first.to_sym]
-      end
     else
       @calls_by_method[method.to_sym]
     end