Do not apply version scripts to DSO symbols

This is needed by Gentoo's dev-perl/Image-Imlib2-2.30.0-r1 package
because this fixes a mis-link issue of libbsd.

passes.cc

@@ -512,7 +512,9 @@ void apply_version_script(Context<E> &ctx) {
 
     if (!elem.is_extern_cpp &&
         elem.pattern.find('*') == elem.pattern.npos) {
-      Symbol<E>::intern(ctx, elem.pattern)->ver_idx = elem.ver_idx;
+      Symbol<E> *sym = Symbol<E>::intern(ctx, elem.pattern);
+      if (sym->file && !sym->file->is_dso)
+        sym->ver_idx = elem.ver_idx;
       continue;
     }
 

test/version-script6.sh

@@ -0,0 +1,41 @@
+#!/bin/bash
+set -e
+cd $(dirname $0)
+echo -n "Testing $(basename -s .sh $0) ... "
+t=$(pwd)/tmp/$(basename -s .sh $0)
+mkdir -p $t
+
+cat <<'EOF' > $t/a.ver
+VER_X1 { foo; };
+VER_X2 { bar; };
+EOF
+
+cat <<EOF | c++ -fPIC -c -o $t/b.o -xc -
+int foo = 5;
+int bar = 6;
+EOF
+
+clang -fuse-ld=`pwd`/../mold -shared -Wl,--version-script=$t/a.ver \
+  -o $t/c.so $t/b.o
+
+cat <<'EOF' > $t/d.ver
+VER_Y1 { local; *; };
+VER_Y2 { baz; };
+VER_Y3 { foo; };
+EOF
+
+cat <<EOF | c++ -fPIC -c -o $t/e.o -xc -
+extern int foo;
+extern int bar;
+int baz() { return foo + bar; }
+EOF
+
+clang -fuse-ld=`pwd`/../mold -shared -Wl,-version-script,$t/d.ver \
+  -o $t/f.so $t/e.o $t/c.so
+
+readelf --dyn-syms $t/f.so > $t/log
+grep -q 'foo@VER_X1' $t/log
+grep -q 'bar@VER_X2' $t/log
+grep -q 'baz@@VER_Y2' $t/log
+
+echo OK