Merge pull request #3584 from bytecodealliance/pch/rust_1.57_warnings

cranelift codegen & filetests: silence new dead code warnings in rust 1.57

cranelift/codegen/src/machinst/blockorder.rs

@@ -86,6 +86,7 @@ pub struct BlockLoweringOrder {
     lowered_order: Vec<LoweredBlock>,
     /// Successors for all lowered blocks, in one serialized vector. Indexed by
     /// the ranges in `lowered_succ_ranges`.
+    #[allow(dead_code)]
     lowered_succs: Vec<(Inst, LoweredBlock)>,
     /// BlockIndex values for successors for all lowered blocks, in the same
     /// order as `lowered_succs`.
@@ -96,6 +97,7 @@ pub struct BlockLoweringOrder {
     /// Mapping from CLIF BB to BlockIndex (index in lowered order). Note that
     /// some CLIF BBs may not be lowered; in particular, we skip unreachable
     /// blocks.
+    #[allow(dead_code)]
     orig_map: SecondaryMap<Block, Option<BlockIndex>>,
 }
 

cranelift/filetests/src/runtest_environment.rs

@@ -58,6 +58,7 @@ type HeapMemory = Vec<u8>;
 pub struct RuntestContext {
     /// Store the heap memory alongside the context info so that we don't accidentally deallocate
     /// it too early.
+    #[allow(dead_code)]
     heaps: Vec<HeapMemory>,
 
     /// This is the actual struct that gets passed into the `vmctx`  argument of the tests.

cranelift/filetests/src/test_unwind.rs

@@ -111,6 +111,7 @@ mod windowsx64 {
         version: u8,
         flags: u8,
         prologue_size: u8,
+        #[allow(dead_code)]
         unwind_code_count_raw: u8,
         frame_register: u8,
         frame_register_offset: u8,