Add separate big and little specializations for aligned case; the attempt to combine into a single specialization was selecting the unaligned specialization. Rework speed_test to try to get more meaningful results and cover more test cases.

test/msvc2012/speed_test/speed_test.vcxproj

@@ -60,7 +60,7 @@
       <GenerateDebugInformation>true</GenerateDebugInformation>
     </Link>
     <PostBuildEvent>
-      <Command>"$(TargetDir)\$(TargetName).exe" 1000000</Command>
+      <Command>"$(TargetDir)\$(TargetName).exe" 1</Command>
     </PostBuildEvent>
   </ItemDefinitionGroup>
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
@@ -80,7 +80,7 @@
       <OptimizeReferences>true</OptimizeReferences>
     </Link>
     <PostBuildEvent>
-      <Command>"$(TargetDir)\$(TargetName).exe" 1000000000</Command>
+      <Command>"$(TargetDir)\$(TargetName).exe" 10000000000</Command>
     </PostBuildEvent>
   </ItemDefinitionGroup>
   <ItemGroup>