pixman build failure on linux arm

[nfisher.sr%gmail.com@localhost]

This is on an RPI4 running Linux-Armv7l. I've pasted a short snippet of
a rather long build log to the bottom of this message, long story short
libpixman_iwmmxt_la-pixman-mmx.lo seems to be full of unsupported
instructions.

Adding --disable-arm-iwmmxt to the list of configure arguments allows
the build to proceed without the offending code. Could be easily
patched into the Makefile:

.if ${MACHINE_ARCH} == armv7l
CONFIGURE_ARGS+= --disable-arm-iwmmxt
.endif

However, I've no way to know if this is specific to RPI4, or to armv7l,
or if it might also apply to aarch64, etc. Considering the nature of
the errors I assume it's not Linux specific.

Thanks,
Nathan Fisher

/tmp/ccXDqE77.s:124522: Error: selected processor does not support
`tmcrr wr8,r5,r6' in ARM mode
/tmp/ccXDqE77.s:124545: Error: selected processor does not support
`wunpckilb wr8,wr8,wr2' in ARM mode
/tmp/ccXDqE77.s:124588: Error: selected processor does not support
`wmulul wr8,wr8,wr10' in ARM mode
/tmp/ccXDqE77.s:124596: Error: selected processor does not support
`waddhus wr8,wr8,wr6' in ARM mode
/tmp/ccXDqE77.s:124602: Error: selected processor does not support
`wmulum wr8,wr8,wr4' in ARM mode
/tmp/ccXDqE77.s:124614: Error: selected processor does not support
`tmcrr wr0,r4,r5' in ARM mode
/tmp/ccXDqE77.s:124627: Error: selected processor does not support
`wunpckilb wr0,wr0,wr2' in ARM mode
/tmp/ccXDqE77.s:124640: Error: selected processor does not support
`wshufh wr0,wr0,#255' in ARM mode
/tmp/ccXDqE77.s:124695: Error: selected processor does not support
`wmulul wr0,wr8,wr0' in ARM mode
/tmp/ccXDqE77.s:124719: Error: selected processor does not support
`waddhus wr0,wr0,wr6' in ARM mode
/tmp/ccXDqE77.s:124731: Error: selected processor does not support
`wmulum wr0,wr0,wr4' in ARM mode
/tmp/ccXDqE77.s:124773: Error: selected processor does not support
`wpackhus wr0,wr0,wr2' in ARM mode
/tmp/ccXDqE77.s:124776: Error: selected processor does not support
`tmrrc r0,r1,wr0' in ARM mode
/tmp/ccXDqE77.s:124818: Error: selected processor does not support
`wldrd wr10,[sp],#8' in ARM mode
make[2]: *** [Makefile:1263: libpixman_iwmmxt_la-pixman-mmx.lo] Error 1