Auto merge of #117115 - zetafunction:linking, r=bjorn3

Mark .rmeta files as /SAFESEH on x86 Windows.

Chrome links .rlibs with /WHOLEARCHIVE or -Wl,--whole-archive to prevent the linker from discarding static initializers. This works well, except on Windows x86, where lld complains:

  error: /safeseh: lib.rmeta is not compatible with SEH

The fix is simply to mark the .rmeta as SAFESEH aware. This is trivially true, since the metadata file does not contain any executable code.

Author: bors