Implement basic C API memory functions

lib/runtime-c-api/tests/test-memory.c

@@ -0,0 +1,23 @@
+#include <stdio.h>
+#include "../wasmer.h"
+#include <assert.h>
+#include <stdint.h>
+
+int main()
+{
+    wasmer_memory_t *memory = NULL;
+    wasmer_limits_t descriptor;
+    descriptor.min = 10;
+    descriptor.max = 10;
+    wasmer_memory_result_t memory_result = wasmer_memory_new(&memory, descriptor);
+    printf("Memory result:  %d\n", memory_result);
+    assert(memory_result == WASMER_MEMORY_OK);
+
+    uint32_t len = wasmer_memory_length(memory);
+    printf("Memory pages length:  %d\n", len);
+    assert(len == 10);
+
+    printf("Destroy memory\n");
+    wasmer_memory_destroy(memory);
+    return 0;
+}