Fixed various isolated test missing requires within AS.

Signed-off-by: Santiago Pastorino <santiago@wyeworks.com>

activesupport/test/core_ext/bigdecimal_test.rb

@@ -1,10 +1,12 @@
 require 'abstract_unit'
+require 'bigdecimal'
+require 'active_support/core_ext/big_decimal'
 
 class BigDecimalTest < Test::Unit::TestCase
   def test_to_yaml
     assert_equal("--- 100000.30020320320000000000000000000000000000001\n", BigDecimal.new('100000.30020320320000000000000000000000000000001').to_yaml)
-    assert_equal("--- .Inf\n", BigDecimal.new('Infinity').to_yaml)
-    assert_equal("--- .NaN\n", BigDecimal.new('NaN').to_yaml)
+    assert_equal("--- .Inf\n",  BigDecimal.new('Infinity').to_yaml)
+    assert_equal("--- .NaN\n",  BigDecimal.new('NaN').to_yaml)
     assert_equal("--- -.Inf\n", BigDecimal.new('-Infinity').to_yaml)
   end
 

activesupport/test/core_ext/hash_ext_test.rb

@@ -4,6 +4,7 @@ require 'bigdecimal'
 require 'active_support/core_ext/string/access'
 require 'active_support/ordered_hash'
 require 'active_support/core_ext/object/conversions'
+require 'active_support/inflections'
 
 class HashExtTest < Test::Unit::TestCase
   class IndifferentHash < HashWithIndifferentAccess

activesupport/test/json/encoding_test.rb

@@ -1,5 +1,6 @@
 # encoding: utf-8
 require 'abstract_unit'
+require 'active_support/core_ext/string/inflections'
 require 'active_support/json'
 
 class TestJSONEncoding < Test::Unit::TestCase