[LLD][COFF] Support /MAPINFO flag

This patch adds support for link.exe's /MAPINFO flag to lld-link.exe.

Here is a description of the flag from Microsoft
(https://learn.microsoft.com/en-us/cpp/build/reference/mapinfo-include-information-in-mapfile?view=msvc-170):

 The /MAPINFO option tells the linker to include the specified information in a
 mapfile, which is created if you specify the /MAP option. EXPORTS tells the
 linker to include exported functions.

Reviewed By: rnk

Differential Revision: https://reviews.llvm.org/D134247