Fix GCC 11 -Warray-parameter warning for __sigsetjmp (bug 26647)

This patch fixes part of bug 26647 (-Werror=array-parameter error
building with GCC 11 because of __sigsetjmp being declared using an
array parameter in one header and a pointer parameter in another).

The fix is to split the struct __jmp_buf_tag definition out to a
separate bits/types/ header so it can be included in pthread.h, so
that pthread.h can declare __sigsetjmp with the type contents visible,
so can use an array (as in setjmp.h) rather than a pointer in the
declaration.

Note that several other build failures with GCC 11 remain.  This does
not fix the jmp_buf-related -Wstringop-overflow errors (also discussed
in bug 26647), or -Warray-parameter errors for other functions (bug
26686), or -Warray-bounds errors (bug 26687).

Tested, with older compilers, natively for x86_64 and with
build-many-glibc.py for aarch64-linux-gnu.  Tested with
build-many-glibcs.py with GCC mainline for aarch64-linux-gnu that this
gets past the -Warray-parameter issue for __sigsetjmp (with the next
build failure being the other one discussed in bug 26647).

1 files changed, 1 insertions, 0 deletions

diff --git a/include/bits/types/struct___jmp_buf_tag.h b/include/bits/types/struct___jmp_buf_tag.h
new file mode 100644
index 0000000000..e3250150da
--- /dev/null
+++ b/include/bits/types/struct___jmp_buf_tag.h
@@ -0,0 +1 @@
+#include <setjmp/bits/types/struct___jmp_buf_tag.h>