[SPIR-V][NFC] Require asserts on 2 tests (#75087)

These tests currently fail on asserts, so adding a REQUIRES to make sure
they're skipped on builds with asserts disabled.

Follow-up from #74849

Author: sudonatalie

llvm/test/CodeGen/SPIRV/opencl/device_execution/execute_block.ll

@@ -2,6 +2,7 @@
 
 ; TODO(#60133): Requires updates following opaque pointer migration.
 ; XFAIL: *
+; REQUIRES: asserts
 
 ; CHECK: %[[#bool:]] = OpTypeBool
 ; CHECK: %[[#true:]] = OpConstantTrue %[[#bool]]

llvm/test/CodeGen/SPIRV/transcoding/BuildNDRange_2.ll

@@ -22,6 +22,7 @@
 
 ; TODO(#60133): Requires updates following opaque pointer migration.
 ; XFAIL: *
+; REQUIRES: asserts
 
 ; CHECK-SPIRV-DAG:     %[[#LEN2_ID:]] = OpConstant %[[#]] 2
 ; CHECK-SPIRV-DAG:     %[[#LEN3_ID:]] = OpConstant %[[#]] 3