Bump MINIFFI_MAX_ARGS to 16 (mkxp-z#4)

* MiniFFI: Use MINIFFI_MAX_ARGS instead of literal

* MiniFFI: Document lines that need changing if MINIFFI_MAX_ARGS changes

* Bump MINIFFI_MAX_ARGS to 12

Fixes mkxp-z#2

* Bump MINIFFI_MAX_ARGS to 16

Author: Splendide-Imaginarius

binding/miniffi.cpp

@@ -3,10 +3,14 @@
 
 #if defined(__MINGW64__) || defined(__linux__) || defined(__APPLE__)
 mffi_value miniffi_call_intern(MINIFFI_FUNC target, MiniFFIFuncArgs *p, int nparams) {
-    assert(nparams <= 10);
+    assert(nparams <= MINIFFI_MAX_ARGS);
+    // Be sure to add more args to the below line if MINIFFI_MAX_ARGS is bumped
+    // in the future.
     return target(p->params[0], p->params[1], p->params[2], p->params[3],
                                  p->params[4], p->params[5], p->params[6],
-                                 p->params[7], p->params[8], p->params[9]);
+                                 p->params[7], p->params[8], p->params[9],
+                                 p->params[10], p->params[11], p->params[12],
+                                 p->params[13], p->params[14], p->params[15]);
 }
 #else // 32-bit Windows
 #define INTEL_ASM ".intel_syntax noprefix\n"

binding/miniffi.h

@@ -2,11 +2,16 @@
 
 #include <cstdint>
 
-#define MINIFFI_MAX_ARGS 10l
+#define MINIFFI_MAX_ARGS 16l
 
 #if defined(__linux__) || defined(__APPLE__)
     typedef unsigned long mffi_value;
+    // Be sure to add more args to the below line if MINIFFI_MAX_ARGS is bumped
+    // in the future.
     typedef mffi_value (*MINIFFI_FUNC)(mffi_value, mffi_value,
+                                       mffi_value, mffi_value,
+                                       mffi_value, mffi_value,
+                                       mffi_value, mffi_value,
                                        mffi_value, mffi_value,
                                        mffi_value, mffi_value,
                                        mffi_value, mffi_value,