sv: allow globals in one file to depend on globals in another

This defers the simplification of globals so that globals in one file
may depend on globals in other files. Adds a simplify() call downstream
because globals are appended at the end.

frontends/ast/ast.cc

@@ -1288,7 +1288,6 @@ void AST::process(RTLIL::Design *design, AstNode *ast, bool dump_ast1, bool dump
 			// must be global definition
 			if ((*it)->type == AST_PARAMETER)
 				(*it)->type = AST_LOCALPARAM; // cannot be overridden
-			(*it)->simplify(false, false, false, 1, -1, false, false); //process enum/other declarations
 			design->verilog_globals.push_back((*it)->clone());
 			current_scope.clear();
 		}

frontends/ast/simplify.cc

@@ -192,6 +192,7 @@ void AstNode::annotateTypedEnums(AstNode *template_node)
 		log_assert(current_scope.count(enum_type) == 1);
 		AstNode *enum_node = current_scope.at(enum_type);
 		log_assert(enum_node->type == AST_ENUM);
+		while (enum_node->simplify(true, false, false, 1, -1, false, true)) { }
 		//get width from 1st enum item:
 		log_assert(enum_node->children.size() >= 1);
 		AstNode *enum_item0 = enum_node->children[0];

tests/verilog/parameters_across_files.ys

@@ -0,0 +1,20 @@
+read_verilog -sv <<EOF
+parameter Q = 1;
+EOF
+read_verilog -sv <<EOF
+parameter P = Q;
+module top(
+    output integer out
+);
+    assign out = P;
+    always @*
+        assert (out == 1);
+endmodule
+EOF
+
+hierarchy
+proc
+flatten
+opt -full
+select -module top
+sat -verify -seq 1 -tempinduct -prove-asserts -show-all