Removed unused variables

test/ruby/test_signal.rb

@@ -332,7 +332,6 @@ class TestSignal < Test::Unit::TestCase
     old = trap(:CHLD, 'IGNORE')
     cmd = [ EnvUtil.rubybin, '--disable=gems', '-e' ]
     assert(system(*cmd, 'exit!(0)'), 'no ECHILD')
-    t0 = Process.clock_gettime(Process::CLOCK_MONOTONIC)
     IO.pipe do |r, w|
       pid = spawn(*cmd, "STDIN.read", in: r)
       nb = Process.wait(pid, Process::WNOHANG)

test/ruby/test_thread.rb

@@ -882,15 +882,15 @@ class TestThread < Test::Unit::TestCase
         begin
           begin
             Thread.pass until done
-          rescue => e
+          rescue
             q.push :ng1
           end
           begin
             Thread.handle_interrupt(Object => :immediate){} if Thread.pending_interrupt?
-          rescue RuntimeError => e
+          rescue RuntimeError
             q.push :ok
           end
-        rescue => e
+        rescue
           q.push :ng2
         ensure
           q.push :ng3
@@ -1189,12 +1189,10 @@ q.pop
     bug8433 = '[ruby-core:55102] [Bug #8433]'
 
     mutex = Thread::Mutex.new
-    flag = false
     mutex.lock
 
     th = Thread.new do
       mutex.synchronize do
-        flag = true
         sleep
       end
     end

test/test_unicode_normalize.rb

@@ -45,7 +45,7 @@ class TestUnicodeNormalize
 
   begin
     @@tests ||= read_tests
-  rescue Errno::ENOENT => e
+  rescue Errno::ENOENT
     @@tests ||= []
   end