I am actually trying to build an Apache 2.4 64 bit version of the adaptor for Solaris. I changed the make.config as you indicated below but I eventually get the following error on the build:
/usr/share/apr-1/build-1/libtool: line 8962: /Applications/Xcode.app/Contents/Developer/Toolchains/OSX10.11.xctoolchain/usr/bin/cc: No such file or directory
This is a valid error since the OSX10.11.xctoolchain/usr/bin/cc portion of that path does not exist. I have a /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/cc. From what I can tell the libtool is configured to point to the former for the compiler though. Unfortunately I do not have root access on the box so I can’t create a directory or link and can’t change the libtool configuration.