[oe] [RFC] Remove gcc configure option --enable-target-optspace for powerpc

[Khem Raj]

Hi

I have run into a problem where compiling libgcc with -Os for powerpc SPE
targets caused some symols like _restgpr_Y_x to be referenced in
libgcc_s.so.1 due to gcc generating them for out-of-line prologues which
happens with Os. But these symbols are defined in libgcc.a so when linking 
a shared library which uses libgcc we get errors from linker complaining
that DSO is accessing a hidden symbol from libgcc.a which is a static
archive.

I thought we could remove --enable-target-optspace. In general it is only
used to compiling the gcc libraries e.g. libgcc libstdc++ etc. in OE
context so its not of a much hit on space usage if we let this option go
which would mean that these libraries would be compiled with -O2

I propose to remove this option for all powerpc and we can still leave it
in for other architectures. 

Does this sound reasonable ?

Thanks

-Khem