lld/ELF: Fix repeated linker script errors in more cases

[MaskRay]

Many steps in LinkerScript.cpp are called repeatedly (fixed point iteration). If they call error and errorOrWarning, we may get repeated error messages.

https://reviews.llvm.org/D152170 and #66836 have fixed some issues, but there are more like symbol not found: (#84512 (comment)).

[llvmbot]

@llvm/issue-subscribers-lld-elf

Author: Fangrui Song (MaskRay)

Many steps in LinkerScript.cpp are called repeatedly (fixed point iteration). If they call `error` and `errorOrWarning`, we may get repeated error messages.

https://reviews.llvm.org/D152170 and #66836 have fixed some issues, but there are more like symbol not found: (#84512 (comment)).