[gcc(refs/vendors/riscv/heads/gcc-13-with-riscv-opts)] riscv: Fix -Wincompatible-pointer-types warning during libgcc build

[gcc(refs/vendors/riscv/heads/gcc-13-with-riscv-opts)] riscv: Fix -Wincompatible-pointer-types warning during libgcc build

[Jeff Law]

https://gcc.gnu.org/g:182bf3fbbbf0a7d4a2e06c0842e089bb8d8b5434

commit 182bf3fbbbf0a7d4a2e06c0842e089bb8d8b5434
Author: Florian Weimer <fweimer@redhat.com>
Date:   Fri Oct 13 09:34:36 2023 +0200

    riscv: Fix -Wincompatible-pointer-types warning during libgcc build
    
    libgcc/
    
            * config/riscv/linux-unwind.h (riscv_fallback_frame_state): Add
            missing cast.
    
    (cherry picked from commit fbd3923887b40c90e7da7323cd0338f23339d888)

Diff:
---
 libgcc/config/riscv/linux-unwind.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libgcc/config/riscv/linux-unwind.h b/libgcc/config/riscv/linux-unwind.h
index 931c2f2795d3..e58d0f4113e2 100644
--- a/libgcc/config/riscv/linux-unwind.h
+++ b/libgcc/config/riscv/linux-unwind.h
@@ -64,7 +64,7 @@ riscv_fallback_frame_state (struct _Unwind_Context *context,
     return _URC_END_OF_STACK;
 
   rt_ = context->cfa;
-  sc = &rt_->uc.uc_mcontext;
+  sc = (struct sigcontext *) &rt_->uc.uc_mcontext;
 
   new_cfa = (_Unwind_Ptr) sc;
   fs->regs.cfa_how = CFA_REG_OFFSET;