patch 8.2.2597: Vim9: "import * as" does not work at script level

Problem:    Vim9: "import * as" does not work at script level.
Solution:   Implement using an imported namespace.
diff --git a/src/vim9execute.c b/src/vim9execute.c
index d4435c4..f8470f5 100644
--- a/src/vim9execute.c
+++ b/src/vim9execute.c
@@ -1765,7 +1765,7 @@
 			goto failed;
 		    SOURCING_LNUM = iptr->isn_lnum;
 		    if (eval_variable(name, (int)STRLEN(name),
-				  STACK_TV_BOT(0), NULL, TRUE, FALSE) == FAIL)
+			      STACK_TV_BOT(0), NULL, EVAL_VAR_VERBOSE) == FAIL)
 			goto on_error;
 		    ++ectx.ec_stack.ga_len;
 		}