Clearing the old systrace plumbing to make way for improved one

[mganandraj]

Please select one of the following

• I am removing an existing difference between facebook/react-native and microsoft/react-native 👍
• I am cherry-picking a change from Facebook's react-native into microsoft/react-native 👍
• I am making a fix / change for the macOS implementation of react-native
• I am making a change required for Microsoft usage of react-native

Description of changes

Systrace is a tracing framework used by Facebook. The implementation of the tracing framework (which they call fbsystrace) is not available in open source. But, all the systrace markers are present in the react native code. In the past we had used these markers in various ways to generate performance tracing and telemetry. The tracing statements gets enabled using a conditional compilation flag "WITH_FBSYSTRACE". The current plubming has a number of deficiencies,

1. It breaks c++ odr rule, which requires all the components which includes the react-native headers to have set the WITH_FBSYSTRACE flag, or risk random crashes.
2. It is very windows & chakra specific.
3. SystraceSection is very badly patched so that it is hard to maintain, if not divergent from the FB code, making it hard to reconcile new changes upstream.

Our new approach is supposed to fix all these. These will be another PR in the RNW repo with the new plumbing.

Focus areas to test

Only the tracing.

Microsoft Reviewers: Open in CodeFlow

[pull-bot]

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[tudorms]