wasm: support more vendor libraries

Adds support for:
- box2d
- cgltf
- stb image
- stb rect pack

vendor/libc/include/stdio.h

@@ -0,0 +1,47 @@
+#include <stddef.h>
+#include <stdarg.h>
+
+#pragma once
+
+typedef struct {} FILE;
+
+#define SEEK_SET 0
+#define SEEK_CUR 1
+#define SEEK_END 2
+
+#define stdout ((FILE *)2)
+#define stderr ((FILE *)3)
+
+FILE *fopen(const char *, char *);
+int fclose(FILE *);
+int fseek(FILE *, long, int);
+long ftell(FILE *);
+size_t fread(void *, size_t, size_t, FILE *);
+size_t fwrite(const void *, size_t, size_t, FILE *);
+
+int vfprintf(FILE *, const char *, va_list);
+int vsnprintf(char *, size_t, const char *, va_list);
+
+static inline int snprintf(char *buf, size_t size, const char *fmt, ...) {
+	va_list args;
+	va_start(args, fmt);
+	int result = vsnprintf(buf, size, fmt, args);
+	va_end(args);
+	return result;
+}
+
+static inline int fprintf(FILE *f, const char *fmt, ...) {
+	va_list args;
+	va_start(args, fmt);
+	int result = vfprintf(f, fmt, args);
+	va_end(args);
+	return result;
+}
+
+static inline int printf(const char *fmt, ...) {
+	va_list args;
+	va_start(args, fmt);
+	int result = vfprintf(stdout, fmt, args);
+	va_end(args);
+	return result;
+}