Revert "ac: use LLVMContextSetOpaquePointers if available"

This reverts commit 940734630d.

radeonsi and radv now support opaque pointers.

Reviewed-by: Mihai Preda <mhpreda@gmail.com>
Reviewed-by: Dave Airlie <airlied@redhat.com>
Reviewed-by: Qiang Yu <yuq825@gmail.com>
Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Acked-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/19035>

src/amd/llvm/ac_llvm_build.c

@@ -62,9 +62,6 @@ void ac_llvm_context_init(struct ac_llvm_context *ctx, struct ac_llvm_compiler *
                           unsigned ballot_mask_bits)
 {
    ctx->context = LLVMContextCreate();
-   #if LLVM_VERSION_MAJOR >= 15
-   LLVMContextSetOpaquePointers(ctx->context, false);
-   #endif
 
    ctx->gfx_level = gfx_level;
    ctx->family = family;