Remove ModuleEnvironment::get_func_name, which is unused.

lib/wasm/src/environ/dummy.rs

@@ -342,10 +342,6 @@ impl<'data> ModuleEnvironment<'data> for DummyEnvironment {
         self.info.config
     }
 
-    fn get_func_name(&self, func_index: FuncIndex) -> ir::ExternalName {
-        get_func_name(func_index)
-    }
-
     fn declare_signature(&mut self, sig: &ir::Signature) {
         self.info.signatures.push(sig.clone());
     }

lib/wasm/src/environ/spec.rs

@@ -235,9 +235,6 @@ pub trait ModuleEnvironment<'data> {
     /// Get the information needed to produce Cranelift IR for the current target.
     fn target_config(&self) -> TargetFrontendConfig;
 
-    /// Return the name for the given function index.
-    fn get_func_name(&self, func_index: FuncIndex) -> ir::ExternalName;
-
     /// Declares a function signature to the environment.
     fn declare_signature(&mut self, sig: &ir::Signature);