[SYCL][NVPTX] Fix wrong pulldown merge

Return back additional switch for test, that was introduced in #5900

Author: Pavel V Chupin

llvm/test/CodeGen/NVPTX/param-load-store.ll

@@ -1,5 +1,5 @@
 ; Verifies correctness of load/store of parameters and return values.
-; RUN: llc < %s -march=nvptx64 -mcpu=sm_35 -O0 -verify-machineinstrs | FileCheck -allow-deprecated-dag-overlap %s
+; RUN: llc < %s -march=nvptx64 -mcpu=sm_35 -O0 -verify-machineinstrs -use-ipsccp-nvptx-O0=false | FileCheck -allow-deprecated-dag-overlap %s
 ; RUN: %if ptxas %{ llc < %s -march=nvptx64 -mcpu=sm_35 -O0 -verify-machineinstrs | %ptxas-verify -arch=sm_35 %}
 
 %s_i1 = type { i1 }