[LibOS] remove unnecessary migrated_shim_addr and __load_address

remove duplicated unused migrated_shim_addr because it's unused.
remove definition of __load_address because it's defined by linker script.

Signed-off-by: Isaku Yamahata <isaku.yamahata@gmail.com>

LibOS/shim/src/elf/shim_rtld.c

@@ -1469,9 +1469,6 @@ int remove_loaded_libraries (void)
     return 0;
 }
 
-void * __load_address;
-void * migrated_shim_addr __attribute_migratable = &__load_address;
-
 int init_internal_map (void)
 {
     __load_elf_object(NULL, &__load_address, OBJECT_INTERNAL, NULL);

LibOS/shim/src/shim_init.c

@@ -168,7 +168,6 @@ long int glibc_option (const char * opt)
 
 void * migrated_memory_start;
 void * migrated_memory_end;
-void * migrated_shim_addr;
 
 const char ** initial_envp __attribute_migratable;