Build system: fix for MinGW-TDM 4.5

(cherry picked from commit 69b9b7fc)

m4/ax_mexopts.m4

@@ -62,7 +62,7 @@ case ${MATLAB_ARCH} in
         ;;
     esac
     MATLAB_LDFLAGS="-static-libgcc -shared \$(top_srcdir)/mex.def"
-    MATLAB_LIBS="$LIBLOC/libmex.lib $LIBLOC/libmx.lib $LIBLOC/libmwlapack.lib -lstdc++"
+    MATLAB_LIBS="$LIBLOC/libmex.lib $LIBLOC/libmx.lib $LIBLOC/libmwlapack.lib"
     # Starting from MATLAB 7.5, BLAS and LAPACK are in distinct libraries
     AX_COMPARE_VERSION([$MATLAB_VERSION], [ge], [7.5], [MATLAB_LIBS="${MATLAB_LIBS} $LIBLOC/libmwblas.lib"])
     ax_mexopts_ok="yes"