Drop use of add_lldb_unittest
Drop use of add_lldb_unittest

lldb unittests depend on libcxx which we have no other use for. Using
the llvm unittest macro avoids that.

Change-Id: Ib44defc112979183c4df8b074d4245b93fcf0c9d
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/2178578
Reviewed-by: Kim-Anh Tran <a72f38a79b5fac6811022b8a7fb84830d856c9c9@chromium.org>
Commit-Queue: Philip Pfaffe <639a645feae3653b7aaefa0387217d375f2f82ff@chromium.org>

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