Do not blindly emplace in interner.
Do not blindly emplace in interner.

This reduces CPU usage of RecordMalloc by another 10% compared to only
using an unordered_set.

See pprof
e027a0ee8c4a0a3c01139a5f5c3368a6 vs 55c67095e15e463abd0fa83aa73b7ad5.

Bug: 126724929
Change-Id: I2dfa0347798e3fbf3652403ebd0bc563c85cc955
google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto