compile error on gcc 4.8.5

[daydream-boost]

Describe the bug
compile error

Your environment

• OS: [CentOS Linux release 7.4.1708 x64]
• Compiler [gcc 4.8.5]

Additional context

In file included from test.c:1:0:
yyjson.h:260:53: error: conflicting declaration ‘typedef long long int int64_t’
         __extension__ typedef long long             int64_t;
                                                     ^
In file included from /usr/include/stdlib.h:314:0,
                 from yyjson.h:18,
                 from test.c:1:
/usr/include/sys/types.h:197:1: error: ‘int64_t’ has a previous declaration as ‘typedef long int int64_t’
 __intN_t (64, __DI__);
 ^

[ibireme]

It seems that yyjson cannot not find stdint.h. As a workaround, you may define YYJSON_HAS_STDINT_H=1 for your project.

I will fix it later.