## What?
Implement `areInlineCompatible` for the SystemZ target using
FeatureBitset comparison.
## Why?
The default implementation in `TargetTransformInfoImpl.h` makes a string
comparison and only inlines when the target-cpu and the target-features
for caller and callee are the same. We are missing out on optimizations
when the callee has a subset of features of the caller.
## How?
Get the FeatureBitset of the caller and callee and check when callee is
a subset or equal to the caller's features. It's a similar
implementation to ARM, PowerPC...
## Testing?
Test cases check for when the callee is a subset of the caller, when
it's not a subset and when both are equals.
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