guix: drop Windows broken-longjmp.patch

Based on Bitcoin PR #28328

contrib/guix/manifest.scm

@@ -149,8 +149,7 @@ desirable for building Feather Wallet release binaries."
 (define (gcc-mingw-patches gcc)
   (package-with-extra-patches gcc
     (search-our-patches "gcc-remap-guix-store.patch"
-                        "vmov-alignment.patch"
+                        "vmov-alignment.patch")))
-                        "gcc-broken-longjmp.patch")))
 
 (define (make-mingw-pthreads-cross-toolchain target)
   "Create a cross-compilation toolchain package for TARGET"

contrib/guix/patches/gcc-broken-longjmp.patch

@@ -1,68 +0,0 @@
-commit eb5698897c52702498938592d7f76e67d126451f
-Author: Eric Botcazou <ebotcazou@adacore.com>
-Date:   Wed May 5 22:48:51 2021 +0200
-
-    Fix PR target/100402
-    
-    This is a regression for 64-bit Windows present from mainline down to the 9
-    branch and introduced by the fix for PR target/99234.  Again SEH, but with
-    a twist related to the way MinGW implements setjmp/longjmp, which turns out
-    to be piggybacked on SEH with recent versions of MinGW, i.e. the longjmp
-    performs a bona-fide unwinding of the stack, because it calls RtlUnwindEx
-    with the second argument initially passed to setjmp, which is the result of
-    __builtin_frame_address (0) in the MinGW header file:
-    
-      define setjmp(BUF) _setjmp((BUF), __builtin_frame_address (0))
-    
-    This means that we directly expose the frame pointer to the SEH machinery
-    here (unlike with regular exception handling where we use an intermediate
-    CFA) and thus that we cannot do whatever we want with it.  The old code
-    would leave it unaligned, i.e. not multiple of 16, whereas the new code
-    aligns it, but this breaks for some reason; at least it appears that a
-    .seh_setframe directive with 0 as second argument always works, so the
-    fix aligns it this way.
-    
-    gcc/
-            PR target/100402
-            * config/i386/i386.c (ix86_compute_frame_layout): For a SEH target,
-            always return the establisher frame for __builtin_frame_address (0).
-    gcc/testsuite/
-            * gcc.c-torture/execute/20210505-1.c: New test.
-
-diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
-index 2f838840e96..06ad1b2274e 100644
---- a/gcc/config/i386/i386.c
-+++ b/gcc/config/i386/i386.c
-@@ -6356,12 +6356,29 @@ ix86_compute_frame_layout (void)
- 	 area, see the SEH code in config/i386/winnt.c for the rationale.  */
-       frame->hard_frame_pointer_offset = frame->sse_reg_save_offset;
- 
--      /* If we can leave the frame pointer where it is, do so.  Also, return
-+      /* If we can leave the frame pointer where it is, do so; however return
- 	 the establisher frame for __builtin_frame_address (0) or else if the
--	 frame overflows the SEH maximum frame size.  */
-+	 frame overflows the SEH maximum frame size.
-+
-+	 Note that the value returned by __builtin_frame_address (0) is quite
-+	 constrained, because setjmp is piggybacked on the SEH machinery with
-+	 recent versions of MinGW:
-+
-+	  #    elif defined(__SEH__)
-+	  #     if defined(__aarch64__) || defined(_ARM64_)
-+	  #      define setjmp(BUF) _setjmp((BUF), __builtin_sponentry())
-+	  #     elif (__MINGW_GCC_VERSION < 40702)
-+	  #      define setjmp(BUF) _setjmp((BUF), mingw_getsp())
-+	  #     else
-+	  #      define setjmp(BUF) _setjmp((BUF), __builtin_frame_address (0))
-+	  #     endif
-+
-+	 and the second argument passed to _setjmp, if not null, is forwarded
-+	 to the TargetFrame parameter of RtlUnwindEx by longjmp (after it has
-+	 built an ExceptionRecord on the fly describing the setjmp buffer).  */
-       const HOST_WIDE_INT diff
- 	= frame->stack_pointer_offset - frame->hard_frame_pointer_offset;
--      if (diff <= 255)
-+      if (diff <= 255 && !crtl->accesses_prior_frames)
- 	{
- 	  /* The resulting diff will be a multiple of 16 lower than 255,
- 	     i.e. at most 240 as required by the unwind data structure.  */