add UTIL_ALLOC macro for calloc

src/util.h

@@ -41,6 +41,8 @@ char* arenaCopyCStr(memory_arena* arena,
 	const char* input,
 	u32 max_len = MAX_NAME_LENGTH);
 
+#define UTIL_ALLOC(count, type) (type*) utilAllocate(count, sizeof(type))
+void* utilAllocate(u32 count, u32 type_size);
 char* utilAllocateCStr(const char* str, u32 max_len = 256);
 void utilSafeFree(void* p);
 
@@ -120,6 +122,14 @@ arenaCopyCStr(memory_arena* arena, const char* input, u32 max_len)
 	return out;
 }
 
+void*
+utilAllocate(u32 count, u32 type_size)
+{
+	void* out = std::calloc(count, type_size);
+	assert(out != nullptr);
+	return out;
+}
+
 char*
 utilAllocateCStr(const char* str, u32 max_len)
 {