add template macro to "safely" perform casts w/o breaking strict-aliasing
fix aliasing warnings



git-svn-id: http://skia.googlecode.com/svn/trunk@674 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/gpu/src/GrTextContext.cpp b/gpu/src/GrTextContext.cpp
index 1374a26..0264856 100644
--- a/gpu/src/GrTextContext.cpp
+++ b/gpu/src/GrTextContext.cpp
@@ -211,7 +211,7 @@
         }
         bool success = fDrawTarget->reserveAndLockGeometry(VLAYOUT,
                                                            fMaxVertices, 0,
-                                                           (void**)&fVertices,
+                                                   GrTCast<void**>(&fVertices),
                                                            NULL);
         GrAlwaysAssert(success);
     }