[llvm] [SandboxVec] Add BottomUpVec test flag to build regions from metadata. (PR #111904)

[Arthur Eubanks via llvm-commits]

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@@ -0,0 +1,16 @@
+; RUN: opt -disable-output --passes=sandbox-vectorizer \
+; RUN:    -sbvec-passes=print-instruction-count \
+; RUN:    -sbvec-use-regions-from-metadata %s | FileCheck %s
+
+define i8 @foo(i8 %v0, i8 %v1) {
+  %t0 = add i8 %v0, 1, !sandboxvec !0
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aeubanks wrote:

the reason I asked for this was to make sure `std::distance(R.begin(), R.end())` wasn't checking how far apart instructions were, but rather how many instructions are in the region. if that's already tested somewhere else then ignore my comment

https://github.com/llvm/llvm-project/pull/111904