Merge commit '847190ebd99ffd57dc89bd568a33bf2d5c424129'

* commit '847190ebd99ffd57dc89bd568a33bf2d5c424129':
  configure: Don't assume an aligned stack on clang on windows

Merged-by: James Almer <jamrial@gmail.com>

diff --cc configure
index 9974bc1f55767d9fedfab6c5e370a54fdcc35ced,95e60064401e1bb1a09aa199083a98662ce45285..f2aa2f5262ab7fe1b6ff4b153b027698947675f8
--- 1/configure
--- 2/configure
+++ b/configure
@@@ -6525,8 -4960,16 +6525,17 @@@ elif enabled gcc; the
  elif enabled llvm_gcc; then
      check_cflags -mllvm -stack-alignment=16
  elif enabled clang; then
-     check_cflags -mllvm -stack-alignment=16
-     check_cflags -mstack-alignment=16
+     if [ "$target_os" = "mingw32" -o "$target_os" = "win32" ] && enabled x86_32; then
+         # Clang doesn't support maintaining alignment without assuming the
+         # same alignment in every function. If 16 byte alignment would be
+         # enabled, one would also have to either add attribute_align_arg on
+         # every single entry point into the libraries or enable -mstackrealign
+         # (doing stack realignment in every single function).
+         disable aligned_stack
+     else
+         check_cflags -mllvm -stack-alignment=16
++        check_cflags -mstack-alignment=16
+     fi
      check_cflags -Qunused-arguments
      check_cflags -Werror=implicit-function-declaration
      check_cflags -Werror=missing-prototypes