Rewrite gdbjit support with safety and fewer deps (#3246)

This refactoring primarily removes the dependency of the gdbjit image
creation on the `finished_functions` array, which shouldn't be necessary
given the input object being passed in since information can be read
from the object instead. Additionally, though, this commit also removes
all `unsafe` from the file, relying on various tools in the `object`
crate to parse the internals and update various fields.

crates/jit/src/instantiate.rs

@@ -213,12 +213,8 @@ impl CompiledModule {
 
         // Register GDB JIT images; initialize profiler and load the wasm module.
         let dbg_jit_registration = if artifacts.native_debug_info_present {
-            let bytes = create_dbg_image(
-                artifacts.obj.to_vec(),
-                code_range,
-                &artifacts.module,
-                &finished_functions,
-            )?;
+            let bytes = create_gdbjit_image(artifacts.obj.to_vec(), code_range)
+                .map_err(SetupError::DebugInfo)?;
             profiler.module_load(&artifacts.module, &finished_functions, Some(&bytes));
             let reg = GdbJitImageRegistration::register(bytes);
             Some(reg)
@@ -407,20 +403,6 @@ impl<'a> SymbolizeContext<'a> {
     }
 }
 
-fn create_dbg_image(
-    obj: Vec<u8>,
-    code_range: (*const u8, usize),
-    module: &Module,
-    finished_functions: &PrimaryMap<DefinedFuncIndex, *mut [VMFunctionBody]>,
-) -> Result<Vec<u8>, SetupError> {
-    let funcs = finished_functions
-        .values()
-        .map(|allocated: &*mut [VMFunctionBody]| (*allocated) as *const u8)
-        .collect::<Vec<_>>();
-    create_gdbjit_image(obj, code_range, module.num_imported_funcs, &funcs)
-        .map_err(SetupError::DebugInfo)
-}
-
 fn build_code_memory(
     obj: &File,
     module: &Module,