Provide proper function index and name in the FrameInfo (#824)

* fix function index

* Add function name to JITFunctionTag

* Add ModuleSyncString.

crates/jit/src/compiler.rs

@@ -166,9 +166,16 @@ impl Compiler {
             let body_len = compilation.get(i).body.len();
             self.jit_function_ranges
                 .push((ptr as usize, ptr as usize + body_len));
+            let func_index = module.func_index(i);
+            let func_name = module
+                .func_names
+                .get(func_index)
+                .cloned()
+                .unwrap_or_else(Default::default);
             let tag = jit_function_registry::JITFunctionTag {
                 module_id: module.name.clone(),
-                func_index: i.index(),
+                func_index: func_index.index(),
+                func_name,
             };
             jit_function_registry::register(ptr as usize, ptr as usize + body_len, tag);
         }

crates/jit/src/instantiate.rs

@@ -16,6 +16,7 @@ use wasmtime_environ::entity::{BoxedSlice, PrimaryMap};
 use wasmtime_environ::wasm::{DefinedFuncIndex, SignatureIndex};
 use wasmtime_environ::{
     CompileError, DataInitializer, DataInitializerLocation, Module, ModuleEnvironment,
+    ModuleSyncString,
 };
 use wasmtime_runtime::{
     Export, GdbJitImageRegistration, Imports, InstanceHandle, InstantiationError, VMFunctionBody,
@@ -76,7 +77,7 @@ impl<'data> RawCompiledModule<'data> {
             None
         };
 
-        translation.module.name = module_name.map(|s| s.to_string());
+        translation.module.name = ModuleSyncString::new(module_name);
 
         let (allocated_functions, jt_offsets, relocations, dbg_image) = compiler.compile(
             &translation.module,