Removed duplicate prototype declarations for bigint
A part of `include/mruby/bigint.h` has been removed because it duplicates `include/mruby/internal.h`.
MODIFY
include/mruby/bigint.h
include/mruby/bigint.h
@@ -85,33 +85,6 @@ struct RBigint {
#define RBIGINT(v) ((struct RBigint*)mrb_ptr(v))
-mrb_value mrb_bint_new_int(mrb_state *mrb, mrb_int x);
-mrb_value mrb_bint_add(mrb_state *mrb, mrb_value x, mrb_value y);
-mrb_value mrb_bint_sub(mrb_state *mrb, mrb_value x, mrb_value y);
-mrb_value mrb_bint_mul(mrb_state *mrb, mrb_value x, mrb_value y);
-mrb_value mrb_bint_div(mrb_state *mrb, mrb_value x, mrb_value y);
-mrb_value mrb_bint_divmod(mrb_state *mrb, mrb_value x, mrb_value y);
-mrb_value mrb_bint_add_ii(mrb_state *mrb, mrb_int x, mrb_int y);
-mrb_value mrb_bint_sub_ii(mrb_state *mrb, mrb_int x, mrb_int y);
-mrb_value mrb_bint_mul_ii(mrb_state *mrb, mrb_int x, mrb_int y);
-mrb_value mrb_bint_div_ii(mrb_state *mrb, mrb_int x, mrb_int y);
-mrb_value mrb_bint_mod(mrb_state *mrb, mrb_value x, mrb_value y);
-mrb_value mrb_bint_rem(mrb_state *mrb, mrb_value x, mrb_value y);
-mrb_value mrb_bint_pow(mrb_state *mrb, mrb_value x, mrb_value y);
-mrb_value mrb_bint_powm(mrb_state *mrb, mrb_value x, mrb_int y, mrb_value z);
-mrb_value mrb_bint_and(mrb_state *mrb, mrb_value x, mrb_value y);
-mrb_value mrb_bint_or(mrb_state *mrb, mrb_value x, mrb_value y);
-mrb_value mrb_bint_xor(mrb_state *mrb, mrb_value x, mrb_value y);
-mrb_value mrb_bint_rev(mrb_state *mrb, mrb_value x);
-mrb_value mrb_bint_lshift(mrb_state *mrb, mrb_value x, mrb_int width);
-mrb_value mrb_bint_rshift(mrb_state *mrb, mrb_value x, mrb_int width);
-mrb_value mrb_bint_to_s(mrb_state *mrb, mrb_value x, mrb_int base);
-#ifndef MRB_NO_FLOAT
-mrb_float mrb_bint_as_float(mrb_state *mrb, mrb_value x);
-#endif
-mrb_int mrb_bint_as_int(mrb_state *mrb, mrb_value x);
-mrb_int mrb_bint_cmp(mrb_state *mrb, mrb_value x, mrb_value y);
-void mrb_gc_free_bint(mrb_state *mrb, struct RBasic *x);
#endif
#endif /* MRB_USE_BIGINT */

Removed duplicate prototype declarations for bigint

A part of `include/mruby/bigint.h` has been removed because it duplicates `include/mruby/internal.h`.