Update src/stdlib_str2num.fypp

Co-authored-by: Jeremie Vandenplas <[email protected]>

Author: jalvesz

src/stdlib_str2num.fypp

@@ -129,10 +129,10 @@ module stdlib_str2num
         character(len=:), pointer :: s !> input string
         real(sp), intent(in) :: mold !> dummy argument to disambiguate at compile time the generic interface
         real(sp) :: r    !> Output real value
-        integer(1),intent(inout), optional :: stat
+        integer(int8), intent(inout), optional :: stat
         ! -- Internal Variables
-        integer(1) :: p !> position within the number
-        integer(1) :: err
+        integer(int8) :: p !> position within the number
+        integer(int8) :: err
         !----------------------------------------------
         call to_num_base(s,r,p,err)
         p = min( p , len(s) )