fixes issue 1159

Fix broken build on VS2005 for drsyms and on pre-7.0 SDK for drwinapi.

git-svn-id: https://dynamorio.googlecode.com/svn/trunk@1942 49cc7528-f6fd-11dd-9d1a-b59b2e1864b6
Use KSTART_DC in dispatch()

Profiling shows that get_thread_private_dcontext() takes 1% of the
time on -native_exec DumpRenderTree.  Currently -native_exec ends up
in dispatch far more often than we would if everything were linked
together in the cache.

Review URL: https://codereview.appspot.com/7376057

git-svn-id: https://dynamorio.googlecode.com/svn/trunk@1944 49cc7528-f6fd-11dd-9d1a-b59b2e1864b6
#error
Merge branch 'master' into native-exec-retstack