add some f2c runtime functions, remove exception, avoid name conflict with libgfortran

lib/linalg/i_lmp_len.cpp

@@ -0,0 +1,10 @@
+
+#include "lmp_f2c.h"
+
+extern "C" {
+
+integer i_lmp_len(char *s, ftnlen n)
+{
+    return (n);
+}
+}