Bug 1233768: Disable regparm under clang-cl in libffi. r=froydnj

js/src/ctypes/libffi-patches/02-clang-cl.patch

@@ -31,7 +31,7 @@ diff --git a/include/ffi.h.in b/include/ffi.h.in
 index 70c6179..ebed0aa 100644
 --- a/include/ffi.h.in
 +++ b/include/ffi.h.in
-@@ -68,7 +68,7 @@ extern "C" {
+@@ -68,7 +68,13 @@
  
  #ifndef LIBFFI_ASM
  
@@ -39,6 +39,12 @@ index 70c6179..ebed0aa 100644
 +#if defined(_MSC_VER) && !defined(__clang__)
  #define __attribute__(X)
  #endif
++
++/* Disable regparm under clang-cl because the assembly thunks were
++   written for MSVC and pass all parameters on the stack. */
++#if defined(_MSC_VER) && defined(__clang__)
++#define regparm(X)
++#endif
  
 diff --git a/msvcc.sh b/msvcc.sh
 index 9208076..4a65b0b 100755

js/src/ctypes/libffi/include/ffi.h.in

@@ -72,6 +72,12 @@ extern "C" {
 #define __attribute__(X)
 #endif
 
+/* Disable regparm under clang-cl because the assembly thunks were
+   written for MSVC and pass all parameters on the stack. */
+#if defined(_MSC_VER) && defined(__clang__)
+#define regparm(X)
+#endif
+
 #include <stddef.h>
 #include <limits.h>