Fix non-Windows tests with \\localhost paths

So they test what they strongly appear to be intending to test: the
behavior of a UNC-style path `\\localhost`. They were instead
testing `\localhost` because `\\` in a non-raw string becomes a
single backslash.

Although the symbolic representations in the assertion messages
were clear enough to identify what the tests intended to test, this
also adjusts those slightly so they remain comparable to the
corresponding Windows tests whose assertion messages were recently
changed.

Author: EliahKagan

gix-fs/tests/stack/mod.rs

@@ -165,14 +165,14 @@ fn path_join_handling() {
     );
 
     assert_eq!(
-        p("/").join("\\localhost"),
-        p("/\\localhost"),
-        "absolute + win-absolute-unc = joined result"
+        p("/").join("\\\\localhost"),
+        p("/\\\\localhost"),
+        "absolute + win-absolute-unc-host = joined result"
     );
     assert_eq!(
-        p("relative").join("\\localhost"),
-        p("relative/\\localhost"),
-        "relative + win-absolute-unc = joined result"
+        p("relative").join("\\\\localhost"),
+        p("relative/\\\\localhost"),
+        "relative + win-absolute-unc-host = joined result"
     );
 }