Add initializers to bound_minimal_symbol

This adds initializers to bound_minimal_symbol, allowing for the
removal of some calls to memset.

gdb/ada-lang.c

@@ -4562,8 +4562,6 @@ ada_lookup_simple_minsym (const char *name)
 {
   struct bound_minimal_symbol result;
 
-  memset (&result, 0, sizeof (result));
-
   symbol_name_match_type match_type = name_match_type_from_name (name);
   lookup_name_info lookup_name (name, match_type);
 

gdb/findvar.c

@@ -404,7 +404,7 @@ symbol_read_needs_frame (struct symbol *sym)
 struct minsym_lookup_data
 {
   /* The name of the minimal symbol we are searching for.  */
-  const char *name;
+  const char *name = nullptr;
 
   /* The field where the callback should store the minimal symbol
      if found.  It should be initialized to NULL before the search
@@ -751,7 +751,6 @@ language_defn::read_var_value (struct symbol *var,
 	struct minimal_symbol *msym;
 	struct obj_section *obj_section;
 
-	memset (&lookup_data, 0, sizeof (lookup_data));
 	lookup_data.name = var->linkage_name ();
 
 	gdbarch_iterate_over_objfiles_in_search_order

gdb/minsyms.h

@@ -31,12 +31,12 @@ struct bound_minimal_symbol
   /* The minimal symbol that was found, or NULL if no minimal symbol
      was found.  */
 
-  struct minimal_symbol *minsym;
+  struct minimal_symbol *minsym = nullptr;
 
   /* If MINSYM is not NULL, then this is the objfile in which the
      symbol is defined.  */
 
-  struct objfile *objfile;
+  struct objfile *objfile = nullptr;
 
   /* Return the obj_section from OBJFILE for MINSYM.  */
 

gdb/value.c

@@ -3171,13 +3171,8 @@ value_fn_field (struct value **arg1p, struct fn_field *f,
   struct bound_minimal_symbol msym;
 
   sym = lookup_symbol (physname, 0, VAR_DOMAIN, 0).symbol;
-  if (sym != NULL)
+  if (sym == nullptr)
     {
-      memset (&msym, 0, sizeof (msym));
-    }
-  else
-    {
-      gdb_assert (sym == NULL);
       msym = lookup_bound_minimal_symbol (physname);
       if (msym.minsym == NULL)
 	return NULL;