Rename `FormulaLock` to `LockFile`.

Library/Homebrew/formula.rb

 require "formula_support"
-require "formula_lock"
+require "lock_file"
 require "formula_pin"
 require "hardware"
 require "utils/bottles"

Library/Homebrew/keg.rb

 require "extend/pathname"
 require "keg_relocate"
-require "formula_lock"
+require "lock_file"
 require "ostruct"
 
 class Keg

Library/Homebrew/formula_lock.rb → Library/Homebrew/lock_file.rb

 require "fcntl"
 
-class FormulaLock
+class LockFile
   def initialize(name)
     @name = name
-    @path = HOMEBREW_LOCK_DIR/"#{@name}.brewing"
+    @path = HOMEBREW_LOCK_DIR/"#{@name}.lock"
     @lockfile = nil
   end
 
@@ -35,3 +35,15 @@ class FormulaLock
     @lockfile.fcntl(Fcntl::F_SETFD, Fcntl::FD_CLOEXEC)
   end
 end
+
+class FormulaLock < LockFile
+  def initialize(name)
+    super("#{name}.formula")
+  end
+end
+
+class CaskLock < LockFile
+  def initialize(name)
+    super("#{name}.cask")
+  end
+end

Library/Homebrew/migrator.rb

 require "formula"
-require "formula_lock"
+require "lock_file"
 require "keg"
 require "tab"
 

Library/Homebrew/test/formula_lock_spec.rb → Library/Homebrew/test/lock_file_spec.rb

-require "formula_lock"
+require "lock_file"
 
-describe FormulaLock do
+describe LockFile do
   subject { described_class.new("foo") }
 
   describe "#lock" do
@@ -24,7 +24,7 @@ describe FormulaLock do
       expect { subject.unlock }.not_to raise_error
     end
 
-    it "unlocks a locked Formula" do
+    it "unlocks when locked" do
       subject.lock
       subject.unlock