[vala/0.40] build: Pass -no-undefined when linking libcodegen

[Rico Tzschichholz <ricotz src gnome org>]

commit e0f9da1ae62f251e398f373e10fad876cba34cd6
Author: Jeremy Philippe <jeremy philippe gmail com>
Date:   Fri Jul 5 18:26:05 2019 +0200

    build: Pass -no-undefined when linking libcodegen
    
    This is required to build under MinGW (and presumably Cygwin).
    
    Fixes https://gitlab.gnome.org/GNOME/vala/issues/820

 codegen/Makefile.am | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/codegen/Makefile.am b/codegen/Makefile.am
index 7dc2d3e6c..09d420ea8 100644
--- a/codegen/Makefile.am
+++ b/codegen/Makefile.am
@@ -19,6 +19,7 @@ libvalaccodegen_la_LTLIBRARIES = \
 libvalaccodegen_ladir = $(pkglibdir)
 
 libvalaccodegen_la_LDFLAGS = \
+       -no-undefined \
        -avoid-version \
        $(NULL)