Certain build time changes are required in order to populate sun.arch.abi Java Property (introduced with JDK-8005545):

a) JDK_ARCH_ABI_PROP_NAME=foo is either passed as a make variable, or set in the environment; and
b) --with-extra-cflags is used to pass -DJDK_ARCH_ABI_PROP_NAME=foo

Those instructions need to be documented in JDK8 README-build.html