c-regress: add ks_free()

...-01-empty-tombstone-value-shouldnt-be-inserted-into-map.c

suite/regress/c-crashers/crash-02-index-lt-size-failed.c

suite/regress/c-crashers/crash-03-invalid-index.c

.../regress/c-crashers/crash-04-readcount-not-equal-to-one.c

...ss/c-crashers/crash-05-normal-symbols-cannot-be-unnamed.c

...ers/crash-06-exponent-has-no-digits-in-apfloat-line-126.c

...ers/crash-07-exponent-has-no-digits-in-apfloat-line-131.c

...crash-08-invalid-character-in-exponent-absexponent-case.c

...shers/crash-09-invalid-character-in-exponent-value-case.c

...crash-10-stringref-cannot-be-built-from-a-null-argument.c

...ash-11-elfobjectwriter-should-not-have-constructed-this.c

...ash-12-cannot-set-a-variable-that-has-already-been-used.c

...13-hexagon-mc-code-emitter-mk-is-not-equal-to-symbolref.c