patch 8.2.3960: error messages are spread out

Problem:    Error messages are spread out.
Solution:   Move more errors to errors.h.
diff --git a/src/alloc.c b/src/alloc.c
index 20df46c..cb781b0 100644
--- a/src/alloc.c
+++ b/src/alloc.c
@@ -224,7 +224,7 @@
     {
 	// Don't hide this message
 	emsg_silent = 0;
-	iemsg(_("E341: Internal error: lalloc(0, )"));
+	iemsg(_(e_internal_error_lalloc_zero));
 	return NULL;
     }
 
@@ -339,7 +339,7 @@
 	// message fails, e.g. when setting v:errmsg.
 	did_outofmem_msg = TRUE;
 
-	semsg(_("E342: Out of memory!  (allocating %lu bytes)"), (long_u)size);
+	semsg(_(e_out_of_memory_allocating_nr_bytes), (long_u)size);
 
 	if (starting == NO_SCREEN)
 	    // Not even finished with initializations and already out of