[liba] Add aeabi long conversion

liba/test/long.c

@@ -0,0 +1,18 @@
+#include <quiz.h>
+#include <stdint.h>
+#include <assert.h>
+
+void assert_int64t_approximatively_equals_int64t(int64_t i, int64_t j) {
+  assert(i-j < 1000000);
+  assert(j-i < 1000000);
+}
+
+QUIZ_CASE(long_arithmetic) {
+  int64_t i = 123456789101112;
+  assert((float)i == 1.23456789101112e14f);
+  assert((double)i == 1.23456789101112e14);
+  float f = 123456789101112.12345f;
+  assert_int64t_approximatively_equals_int64t((int64_t)f, 123456789101112);
+  double d = 123456789101112.12345f;
+  assert_int64t_approximatively_equals_int64t((int64_t)d, 123456789101112);
+}