Instrument: Fix code for version 2 output format. (#2655)

Correct record size. Also bring version 2 tests up to version 1
equivalence.

source/opt/instrument_pass.cpp

@@ -605,7 +605,9 @@ uint32_t InstrumentPass::GetStreamWriteFunctionId(uint32_t stage_idx,
         context(), &*new_blk_ptr,
         IRContext::kAnalysisDefUse | IRContext::kAnalysisInstrToBlockMapping);
     // Gen test if debug output buffer size will not be exceeded.
-    uint32_t obuf_record_sz = kInstStageOutCnt + val_spec_param_cnt;
+    uint32_t val_spec_offset =
+        (version_ == 1) ? kInstStageOutCnt : kInst2StageOutCnt;
+    uint32_t obuf_record_sz = val_spec_offset + val_spec_param_cnt;
     uint32_t buf_id = GetOutputBufferId();
     uint32_t buf_uint_ptr_id = GetBufferUintPtrId();
     Instruction* obuf_curr_sz_ac_inst =
@@ -649,8 +651,6 @@ uint32_t InstrumentPass::GetStreamWriteFunctionId(uint32_t stage_idx,
     GenCommonStreamWriteCode(obuf_record_sz, param_vec[kInstCommonParamInstIdx],
                              stage_idx, obuf_curr_sz_id, &builder);
     GenStageStreamWriteCode(stage_idx, obuf_curr_sz_id, &builder);
-    uint32_t val_spec_offset =
-        (version_ == 1) ? kInstStageOutCnt : kInst2StageOutCnt;
     // Gen writes of validation specific data
     for (uint32_t i = 0; i < val_spec_param_cnt; ++i) {
       GenDebugOutputFieldCode(obuf_curr_sz_id, val_spec_offset + i,