Changes

Summary

[ARM] Some formatting and predicate VRHADD patterns. NFC (details)
[ARM] Allow vecreduce_add in tail predicated loops (details)
[ARM] Add VADDV and VMLAV patterns for v16i16 (details)
[Diagnostics] Turn string concat warning to avoid false positives (details)
[Polly] Reuse LLVM's build rules for gtest/gmock (details)

Commit 296faa91ed55c05b40d286be020fc65d2fc262b5 by david.green [ARM] Some formatting and predicate VRHADD patterns. NFC This formats some of the MVE patterns, and adds a missing Predicates = [HasMVEInt] to some VRHADD patterns I noticed as going through. Although I don't believe NEON would ever use the patterns (as it would use ADDL and VSHRN instead) they should ideally be predicated on having MVE instructions.
	llvm/lib/Target/ARM/ARMInstrMVE.td
Commit 8590e5abad51257fe9120313b37192f37aef8eec by david.green [ARM] Allow vecreduce_add in tail predicated loops This allows vecreduce_add in loops so that we can tailpredicate them. Differential Revision: https://reviews.llvm.org/D85454
	llvm/lib/Target/ARM/MVETailPredication.cpp
	llvm/test/CodeGen/Thumb2/mve-vecreduce-loops.ll
Commit 186a7f81e813a59b68fadfe7ea90c348bb760c56 by david.green [ARM] Add VADDV and VMLAV patterns for v16i16 This adds patterns for v16i16's vecreduce, using all the existing code to go via an i32 VADDV/VMLAV and truncating the result. Differential Revision: https://reviews.llvm.org/D85452
	llvm/test/CodeGen/Thumb2/mve-vecreduce-loops.ll
	llvm/lib/Target/ARM/ARMISelLowering.cpp
	llvm/test/CodeGen/Thumb2/mve-vecreduce-mla.ll
	llvm/test/CodeGen/Thumb2/mve-vecreduce-add.ll
	llvm/test/CodeGen/Thumb2/mve-vecreduce-addpred.ll
	llvm/test/CodeGen/Thumb2/mve-vecreduce-mlapred.ll
Commit 04a23f1fe08a6ad0baf1305d7308231d2cb4843b by Dávid Bolvanský [Diagnostics] Turn string concat warning to avoid false positives
	clang/lib/Sema/SemaExpr.cpp
	clang/test/Sema/string-concat.c
Commit c8b629a3a5854506dd25e84f9b4174b53f8f667b by mgorny [Polly] Reuse LLVM's build rules for gtest/gmock Reuse LLVM's CMakeLists.txt for gtest/gmock instead of reinventing them in Polly. This fixes a lot of linking errors due to not linking LLVMSupport in for me. Differential Revision: https://reviews.llvm.org/D85280
	polly/CMakeLists.txt