[BOLT] Print heatmap from perf2bolt (#139194)
Add perf2bolt `--heatmap` option to produce heatmaps during profile
aggregation.
Distinguish exclusive mode (`llvm-bolt-heatmap`) and optional mode
(`perf2bolt --heatmap`), which impacts perf.data handling:
exclusive mode covers all addresses, whereas optional mode consumes
attached profile only covering function addresses.
Test Plan: updated per2bolt tests:
- pre-aggregated-perf.test: pre-aggregated data,
- bolt-address-translation-yaml.test: pre-aggregated + BOLTed input,
- perf_test.test: no-LBR perf data.
