Don't allow Fortran if without then, fixes #63

test/issues/63/test.f90

@@ -0,0 +1,16 @@
+program matchup_parsing
+  real :: x = 1.0, y = 2.0, a
+
+
+  if (x < y) then
+    if (x == 0) stop
+    a = y / x
+  else
+    if (y == 0) stop  ! matchup sees corresponding `if - end if` pairs from HERE
+    a = x / y
+  end if  ! to HERE
+
+  write(*, *) a
+
+end program
+