Duplicate symbol test.

testdupsym/compile.sh

+gcc -shared -o libl1.so lib1.c 
+gcc -shared -o libl2.so lib2.c
+gcc -o main main.c -L. -ll1 -ll2
+

testdupsym/lib1.c

+int testfun(int x)
+{
+    return x+1;
+}
+

testdupsym/lib2.c

+int testfun(int x)
+{
+    return x+2;
+}
+

testdupsym/main.c

+#include <stdio.h>
+
+int testfun(int);
+
+int main(void)
+{
+    printf("%d\n", testfun(42));
+    return 0;
+}
+