Set ELF_OSABI for x86 and sparc

[Maciej W. Rozycki]

On Sun, 4 Jan 2026, Alan Modra wrote:

> This has the side effect of disabling gnu features that require
> ELFOSABI_GNU, such as ifuncs.  I think that is correct, so I've made
> the required testsuite changes to fix the resulting regressions:
> FAIL: nm --ifunc-chars (assembly)
> FAIL: mbind sections without SHF_ALLOC

 There are more of them though:

x86_64-solaris2  +FAIL: i386 ifunc
x86_64-solaris2  +FAIL: i386 ifunc-2
x86_64-solaris2  +FAIL: i386 ifunc 3
x86_64-solaris2  +FAIL: x86-64 ifunc

e.g.:

.../gas/testsuite/gas/i386/ifunc.s: Assembler messages:
.../gas/testsuite/gas/i386/ifunc.s:5: Error: symbol type "gnu_indirect_function" is supported only by GNU and FreeBSD targets
failed with: <.../gas/testsuite/gas/i386/ifunc.s: 
Assembler messages:
.../gas/testsuite/gas/i386/ifunc.s:5: Error: symbol type "gnu_indirect_function" is supported only by GNU and FreeBSD targets>, no expected output
FAIL: i386 ifunc

  Maciej