building Qt 4.8-TP on RHEL 5.1 fails u32 not declared when compiling qmutex_unix.cpp

when building Qt 4.8-TP on RHEL 5.1 with gcc 4.1.2 compiler
qmutex_unix.cpp does not compile as u32 is not declared

there is a new include of <linux/futex.h> which appears to be using the kernel u32 type, but its not defined

building on a later OS distro, Fedora 14, this does build.