[lld] [LLD] Add CLASS syntax to SECTIONS (PR #95323)

[Fangrui Song via llvm-commits]

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@@ -38,6 +38,13 @@ ELF Improvements
 * ``--debug-names`` is added to create a merged ``.debug_names`` index
   from input ``.debug_names`` sections. Type units are not handled yet.
   (`#86508 <https://github.com/llvm/llvm-project/pull/86508>`_)
+* Section ``CLASS`` syntax allows binding input section to named classes. This
+  allows the linker to automatically pack the input sections into memory
+  regions by automatically spilling to later class references if a region would
+  overflow. This reduces the toil of manually packing regions (typical for
+  embedded). It also makes full LTO feasible in such cases, since IR merging
+  currently prevents the linker script from referring to input files. (TODO: PR
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MaskRay wrote:

This can be updated now.

https://github.com/llvm/llvm-project/pull/95323