1d74db7e8d
DTLTO emits temporary files to allow distribution of archive member inputs. It also emits temporary files from the ThinLTO backend, such as the index files needed for each distributed ThinLTO backend compilation. This change brings archive member temporary files into line with those produced by the ThinLTO backend. They are now emitted in the same location, warnings are emitted if they cannot be deleted, and they are cleaned up on abnormal exit (e.g. Ctrl-C). All temporary files are preserved when --save-temps is specified. The existing signal-handling test has been extended to cover the full set of DTLTO temporary files, and a new test has been added to exercise temporary file handling in normal operation. Additionally, a minimal test has been added to show the COFF behaviour. SIE Internal tracker: TOOLCHAIN-21022
See docs/NewLLD.rst