qt-4.8.6 webkit: fails to compile on MIPS64 n32 platforms

It fails to compile on MIPS64 n32 platforms, at this point:

qt-4.8.6/src/3rdparty/webkit/Source/JavaScriptCore/wtf/Assertions.h:326

/* COMPILE_ASSERT */
#ifndef COMPILE_ASSERT
#define COMPILE_ASSERT(exp, name) typedef int dummy##name [(exp) ? 1 : -1]
#endif

With an error message like this one:

./wtf/StdLibExtras.h: In instantiation of 'TO WTF::bitwise_cast(FROM) [with TO = int; FROM = double]':
runtime/JSValueInlineMethods.h:495:44: required from here
./wtf/Assertions.h:326:47: error: size of array is negative
#define COMPILE_ASSERT(exp, name) typedef int dummy##name [(exp) ? 1 : -1]

MIPS64 n32 is a 64-bit architecture which has 32-bit pointers and 32-bit long integers, so maybe that's the problem here.

A complete build log is attached.