[OFFLOAD] Update ffi_cif structure to match libffi (#128756)

The ffi_cif structure defined in the wrapper header is smaller than the
actual structure in libffi which results in other structures being
overwritten when libffi is called, and finally in a segfault.

The patch updates the structure to the correct layout as specified in
ffi.h

Author: adurang

offload/plugins-nextgen/host/dynamic_ffi/ffi.h

@@ -53,6 +53,16 @@ typedef enum ffi_abi {
 #else
 #error "Unknown ABI"
 #endif
+} ffi_abi;
+
+typedef struct {
+  ffi_abi abi;
+  unsigned nargs;
+  ffi_type **arg_types;
+  ffi_type *rtype;
+  unsigned bytes;
+  unsigned flags;
+  long long extra_fields; // Longest extra field defined in the FFI sources
 } ffi_cif;
 
 #ifdef __cplusplus