Clean up some linker/C compiler options

[MaskRay]

-fno-pic/-fno-pie/-fpic/-fPIC/-fpie/-fPIE options belong to the same famility where the last option wins. These options have no effect in the link phase.

Clang and GCC usually pass --eh-frame-hdr to ld, with the exception that gcc -static does not pass --eh-frame-hdr. The difference is a historical choice related to __register_frame_info. We can behavle like Clang and always pass --eh-frame-hdr.

Remove a -L that does not specify a directory.

[MaskRay]

• https://maskray.me/blog/2020-11-08-stack-unwinding#eh_frame_hdr-and-pt_gnu_eh_frame
• small PIC is only relevant for Sparc and 32-bit PowerPC. Likely not interesting

Side notes (not done in this PR as I am not familiar with the use cases)

• --export-dynamic, only relevant for executable, probably should not be coupled with DEBUG_INFO_FULL. It could make .dynsym very large
• --gc-sections could be enabled for -shared as well. Defined symbols that are exported to .dynsym will not be garbage collected. https://maskray.me/blog/2021-02-28-linker-garbage-collection#ld.lld

[lerno]

For pie/pic/PIE/PIC here I've tried to follow Clang mostly. I see you removed a bunch of options, but pie and pic are interdependent in Clang what I could note.

[MaskRay]

For pie/pic/PIE/PIC here I've tried to follow Clang mostly. I see you removed a bunch of options, but pie and pic are interdependent in Clang what I could note.

For -fpic/-fpie/-fno-pic/-fno-pie options the last wins: https://github.com/llvm/llvm-project/blob/05a09e6e559e8253d49cc61052711f0c200129bf/clang/lib/Driver/ToolChains/CommonArgs.cpp#L1907

Regarding the module flags metadata "PIC Level" and "PIE Level". They are independent.

[lerno]

All right, good!

[lerno]

Thank you!