DRTVWR-418: Migrate HAVOK suppression from autobuild.xml to build.sh.

Turns out that without HAVOK, we can't build the PhysicsExtensions_TPV; but
the viewer's build.sh is unaware of CMake switches set in autobuild.xml.
Passing those CMake overrides in build.sh allows us to test that setting
elsewhere in build.sh to skip the PhysicsExtensions_TPV step -- instead of
failing the build.

autobuild.xml

@@ -3344,7 +3344,6 @@
                 <array>
                   <string>-G</string>
                   <string>Xcode</string>
-                  <string>-DHAVOK:BOOL=FALSE</string>
                 </array>
               </map>
               <key>default</key>
@@ -3407,7 +3406,6 @@
                 <array>
                   <string>-G</string>
                   <string>Xcode</string>
-                  <string>-DHAVOK:BOOL=FALSE</string>
                 </array>
               </map>
               <key>name</key>

build.sh

@@ -95,16 +95,20 @@ pre_build()
     && [ -r "$master_message_template_checkout/message_template.msg" ] \
     && template_verifier_master_url="-DTEMPLATE_VERIFIER_MASTER_URL=file://$master_message_template_checkout/message_template.msg"
 
+    # nat 2016-12-20: disable HAVOK on Mac until we get a 64-bit Mac build.
     # nat 2016-12-21: disable generate_breakpad_symbols.py on Mac until we
     # figure out why it's breaking.
     if [ "$arch" == "Darwin" ]
-    then RELEASE_CRASH_REPORTING=OFF
-    else RELEASE_CRASH_REPORTING=ON
+    then HAVOK=OFF
+         RELEASE_CRASH_REPORTING=OFF
+    else HAVOK=ON
+         RELEASE_CRASH_REPORTING=ON
     fi
 
     "$autobuild" configure --quiet -c $variant -- \
      -DPACKAGE:BOOL=ON \
      -DUNATTENDED:BOOL=ON \
+     -DHAVOK:BOOL="$HAVOK" \
      -DRELEASE_CRASH_REPORTING:BOOL="$RELEASE_CRASH_REPORTING" \
      -DVIEWER_CHANNEL:STRING="\"$viewer_channel\"" \
      -DGRID:STRING="\"$viewer_grid\"" \
@@ -119,7 +123,8 @@ package_llphysicsextensions_tpv()
 {
   begin_section "PhysicsExtensions_TPV"
   tpv_status=0
-  if [ "$variant" = "Release" ]
+  # nat 2016-12-21: without HAVOK, can't build PhysicsExtensions_TPV.
+  if [ "$variant" = "Release" -a "${HAVOK:-}" != "OFF" ]
   then 
       test -r  "$build_dir/packages/llphysicsextensions/autobuild-tpv.xml" || fatal "No llphysicsextensions_tpv autobuild configuration found"
       tpvconfig=$(native_path "$build_dir/packages/llphysicsextensions/autobuild-tpv.xml")