hppa: avoid TEXTREL in .eh_frame section (#447)
hppa: avoid TEXTREL in .eh_frame section (#447)

Before the change hand-crafted .eh_frame section contained
ABS relocation and caused TEXTREL tag to be emitted:

```
$ ./configure --host=hppa2.0-unknown-linux-gnu LDFLAGS=-Wl,-z,text
$ make
...
/usr/libexec/gcc/hppa2.0-unknown-linux-gnu/ld:
    read-only segment has dynamic relocations.
```

Link failure is caused by absolute address of FDEs
encoded into .eh_frame entries.

Fixed TEXTREL by using pcrel (instead of ABS) encoding
for absolute addresses (__PIC__ code) by adding augmentation
information ("zR" CIE type).

All tests still pass on hppa2.0. The specific tests that still pass
and exercise this code path:
    testsuite/libffi.call/unwindtest.cc
    testsuite/libffi.call/unwindtest_ffi_call.cc

Signed-off-by: Sergei Trofimovich <110fdadc76b6bce16977f568bdb4723eaed6fb3f@gentoo.org>
plicease/libffi,plicease/libffi,plicease/libffi,plicease/libffi