libFFI recipe doesn't work with clang

[inclement]

I tested building with NDK 19, with which we need to use clang. Thanks to the work adding clang support this seems to work fine, at least with the core recipes I tested.

However, libFFI failed to build with the following error:

/home/sandy/android/android-ndk-r19/sysroot -I/home/sandy/.local/share/python-for-android/build/python-installs/bdisttest_python3_googlendk/include/python3.7 -march=armv7-a -mfloat-abi=softfp -mfpu=vfp -mthumb -Wall -fexceptions -MT src/prep_cif.lo -MD -MP -MF src/.deps/prep_cif.Tpo -c ../src/prep_cif.c -o src/prep_cif.o >/dev/null 2>&1
../src/arm/sysv.S:363:2: error: invalid instruction, did you mean: fldmiax?
 fldmiadgt ip, {d0-d7}
 ^
../src/arm/sysv.S:399:2: error: invalid instruction
 stmeqia r2, {r0, r1}
 ^
../src/arm/sysv.S:412:2: error: invalid instruction, did you mean: fstmiax?
 fstmiadeq r2, {d0-d3}
 ^
/tmp/sysv-9bd638.s:263:2: error: invalid instruction
 fstmfdd sp!, {d0-d7}
 ^
/tmp/sysv-9bd638.s:313:2: error: invalid instruction, did you mean: fldmiax?
 fldmiad sp, {d0-d1}
 ^
/tmp/sysv-9bd638.s:316:2: error: invalid instruction, did you mean: fldmiax?
 fldmiad sp, {d0-d3}

Googling resulted in some relevant results so hopefully this can be fixed easily enough.

[inclement]

Duplicate of #1525