Partial hashing of module for faster caching (#221)

* Simple module compilation cache

* Fix base64 encoding bug

* Use warn! everywhere in cache system

* Remove unused import

* Temporary workaround for long path on Windows

* Remove unused import for non-windows builds

* Add command line argument to enable cache system + apply minor review feedback

* Initial implementation of partial module hashing

* Proper module hashing for the cache

* Use newer version of cranelift

wasmtime-environ/src/cranelift.rs

@@ -124,7 +124,13 @@ impl crate::compilation::Compiler for Cranelift {
         isa: &dyn isa::TargetIsa,
         generate_debug_info: bool,
     ) -> Result<(Compilation, Relocations, ModuleAddressMap), CompileError> {
-        let cache_entry = ModuleCacheEntry::new(module, isa, "cranelift", generate_debug_info);
+        let cache_entry = ModuleCacheEntry::new(
+            module,
+            &function_body_inputs,
+            isa,
+            "cranelift",
+            generate_debug_info,
+        );
 
         let data = match cache_entry.get_data() {
             Some(data) => data,