rlibs are not bit-identical when building the same crate in different directories with -Zremap-path-prefix #48019
Description
I was trying to determine if sccache could cache crates built as dependencies of different root crates. When I looked into it I found that the rlibs were not bit-identical despite being built from the same source. Most of the differences were in the debug info because the current directory winds up encoded there. I tried using -Zremap-path-prefix-from=... -Zremap-path-prefix-to=... which removed most of the differences but not all. A small difference in the metadata remains, which from looking at the diff of the serialized metadata @eddyb said was the SVH. @michaelwoerister: do you know why this would be?
I built this test crate twice in different directories using the test-build.sh script. The diff of the itoa rlib from each build looks like this (I generated that using diffoscope.)