[AArch64] Inline callee if its target-features are a subset of the caller

[AArch64] Inline callee if its target-features are a subset of the caller

Summary:
Similar to X86, it should be safe to inline callees if their target-features
are a subset of the caller. This change matches GCC's inlining behavior
with respect to attributes [1].

[1] https://gcc.gnu.org/onlinedocs/gcc/AArch64-Function-Attributes.html#AArch64-Function-Attributes

Reviewers: kristof.beyls, javed.absar, rengolin, t.p.northover

Reviewed By: t.p.northover

Subscribers: aemerson, eraman, llvm-commits

Differential Revision: https://reviews.llvm.org/D34698

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@306478 91177308-0d34-0410-b5e6-96231b3b80d8