ld.lld: translate TARGET2 reloc to relative address relocation

[occheung]

ARTIQ Pull Request

Description of Changes

This PR changes the interpretation of R_ARM_TARGET2 relocation from PC-relative offset from a GOT entry, to a simple RC-relative offset.

It bypasses the generation of GOT entries for exception type for ARM target. Adjustment to the exception table parser is in the corresponding patch to artiq-zynq.

Related PR

artiq-zynq PR 192

Test

Applied the corresponding patch in artiq-zynq. Passed tests artiq.test regarding exceptions (e.g. test_nested_exceptions).

Type of Changes

	Type
✓	🔨 Refactoring

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Code Changes

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• Check, test, and update the unittests in /artiq/test/ or gateware simulations in /artiq/gateware/test

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Licensing

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ARTIQ files that do not contain a license header are copyrighted by M-Labs Limited and are licensed under LGPLv3+.

[sbourdeauducq]

Thanks!

The coding style is a bit unusual with the ancestor class referencing a derived class. I suggest introducing another parameter similar to the existing ones (triple, data_layout, tool_ld, ...) which declares additional linker command-line options instead.