[ddc] Fix equals operator on native types
[ddc] Fix equals operator on native types

Emit `===` instead of `[$equals]` when the LHS is represented as a
primitive type.

The calculation of the left type was resulting in Object instead of a
more precise type. This caused the check for primitives types to always
fail.

Provides 20%+ performance improvements on the Wordsolver and
CollectionSieves-removeWhere benchmarks.
https://golem.corp.goog/Comparison?repository=dart&team=dartdevc#targetA%3Ddartdevc%3BmachineTypeA%3Dlinux-x64%3BrevisionA%3D89773%3BpatchA%3Dnshahan-fix-primative-equals%3BtargetB%3Ddartdevc%3BmachineTypeB%3Dlinux-x64%3BrevisionB%3D89771%3BpatchB%3DNone

Change-Id: Ica980f28bf8df627571b9aa53e77478e2b1de17f
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/176069
Reviewed-by: Sigmund Cherem <beaea8fd7d2a56555046ba4f362c8a93e3938576@google.com>
Reviewed-by: Mark Zhou <654f5fe0c4ca6c799b0e735dcf3fc1c389f35bf9@google.com>
Commit-Queue: Nicholas Shahan <03847abd2d8aadfe859ecb98095a31f9f515dc47@google.com>

dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk