This commit reverts 338930. The approach was wrong.

Fix the issue with subtracting the TLS_TCB_SIZE too when we are trying to get
the 'where' in the R_PPC_TPREL32 case. At allocation time we added an offset
and the TLS_TCB_SIZE. This has to be subtracted as well.

Now all the issues reported are fixed. Tests were done on G4 and G5 PowerMac's.
Additionally I ran the tls tests from the gcc test suite and made sure the
results are as good as pre 338486.

Thanks to tuexen for reporting the malfunction and for patient testing.
Also testing thanks goes to jhibbits.

Reported by: tuexen
Discussed with: jhibbits, nwhitehorn
Approved by: re (gjb)
Pointyhat to: andreast