Add -lole32 to link libraries.
This fixes a problem when compiling with mingw-headers version 3.3
where the use of SHGetFolderPath() expands to a call to CoTaskMemFree()
which is defined in libole32.dll:
/usr/x86_64-w64-mingw32/sys-root/mingw/include/shobjidl.h:29954: undefined reference to `__imp_CoTaskMemFree'
1.1 --- a/configure.ac Thu Nov 13 11:30:27 2014 +0000
1.2 +++ b/configure.ac Wed Apr 22 13:09:42 2015 +0100
1.3 @@ -83,7 +83,7 @@
1.4 case $host_os in
1.5 *mingw*) AC_DEFINE([MSWIN_API], 1,
1.6 [Define to 1 to use Microsoft Windows native API.])
1.7 - EXTRA_LIBS='-lshlwapi -lshell32 -lws2_32'
1.8 + EXTRA_LIBS='-lshlwapi -lshell32 -lws2_32 -lole32'
1.9 mswin_api=yes;;
1.10 *) mswin_api=no;;
1.11 esac