wasm: support more vendor libraries

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

vendor/libc/include/math.h

@@ -0,0 +1,21 @@
+#include <stdbool.h>
+
+float sqrtf(float);
+float cosf(float);
+float sinf(float);
+float atan2f(float, float);
+bool isnan(float);
+bool isinf(float);
+double floor(double x);
+double ceil(double x);
+double sqrt(double x);
+double pow(double x, double y);
+double fmod(double x, double y);
+double cos(double x);
+double acos(double x);
+double fabs(double x);
+int abs(int);
+double ldexp(double, int);
+double exp(double);
+float log(float);
+float sin(float);