hg: macosx-port/macosx-port/hotspot: Support building 32-bit HotSpot using Xcode 4.

[astrange at apple.com]

Changeset: dd9ed97191ba
Author:    astrange
Date:      2011-03-21 15:21 -0400
URL:       http://hg.openjdk.java.net/macosx-port/macosx-port/hotspot/rev/dd9ed97191ba

Support building 32-bit HotSpot using Xcode 4.

Xcode 4 doesn't provide g++-4.0, but llvm-g++-4.2 works instead, so use it.
Also prefer llvm-g++-4.2 on Xcode 3.2.6.
Continue to use g++-4.0 for earlier versions.

! make/bsd/makefiles/gcc.make