Rollup merge of #140284 - bend-n:fix-expectation-unmet, r=jieyouxu

remove expect() in `unnecessary_transmutes`

removes expect() from #136083 and fixes #140277
includes regression test

r? lcnr

tests/ui/transmute/auxiliary/unnecessary-transmute-path-remap-ice-140277-trans.rs

@@ -0,0 +1,10 @@
+//@ compile-flags: --remap-path-prefix=/=/non-existent
+// helper for ../unnecessary-transmute-path-remap-ice-140277.rs
+
+#[macro_export]
+macro_rules! transmute {
+    ($e:expr) => {{
+        let e = $e;
+        std::mem::transmute(e)
+    }};
+}

tests/ui/transmute/unnecessary-transmute-path-remap-ice-140277.rs

@@ -0,0 +1,10 @@
+//@ aux-crate: zerocopy=unnecessary-transmute-path-remap-ice-140277-trans.rs
+//@ check-pass
+// tests for a regression in linting for unnecessary transmutes
+// where a span was inacessible for snippet procuring,
+// when remap-path-prefix was set, causing a panic.
+
+fn bytes_at_home(x: [u8; 4]) -> u32 {
+    unsafe { zerocopy::transmute!(x) }
+}
+fn main() {}