roms/seabios-hppa can't be built with gcc-10: -fno-ipa-sra

[Michael Tokarev]

Switching to gcc-10 makes seabios-hppa unbuildable.
It fails at the final linking step with a lot of
missing references to memcpy & memcmp all over the
places.

The notable difference between gcc-10 and previous
gcc is that ccode32flat.o does _not_ have the text
for these two functions but have two .isra.0:

$ hppa-linux-gnu-nm ccode32flat.o | grep mem[sc]
000003e0 t memcmp
         U memcpy
00002f38 t memcpy.isra.0
         U memset
00003a84 t memset.isra.0


while previous version of the compiler did have them:

$ hppa-linux-gnu-nm ccode32flat.o | grep mem[sc]
000002fc t memcmp
0000370c t memcpy
0000036c t memset

After adding -fno-ipa-sra to the gcc flags, the firmware
is built successfully.

I don't know what to make out of this. Previous versions
of gcc apparently accepts -fno-ipa-sra too, for quite some
time.  So maybe add this to the flags unconditionally?

Thanks,

/mjt