RFC: Add -z text-start-addr=ADDR to ELF linker

[Ian Lance Taylor]

"H.J. Lu" <hongjiu.lu@intel.com> writes:

> Sometimes, we want to load the ELF executable in a different address from
> the default.  This patch adds -z text-start-addr=ADDR to ELF linker. If it
> is acceptable, I will submit a complete patch with some testcases.

We already support -Ttext=ADDR and SEGMENT_START.  Does this add
anything to that approach?

Ian