Add MinGW support

ggml.c

@@ -1,6 +1,11 @@
 #include "ggml.h"
 
+#if defined(_MSC_VER) || defined(__MINGW32__)
+#include <malloc.h> // using malloc.h with MSC/MINGW
+#else
 #include <alloca.h>
+#endif
+
 #include <assert.h>
 #include <time.h>
 #include <math.h>

whisper.cpp

@@ -4,6 +4,7 @@
 
 #include <algorithm>
 #include <cassert>
+#define _USE_MATH_DEFINES
 #include <cmath>
 #include <cstdio>
 #include <cstring>