[BPF] Use elementtype attribute for preserve.array/struct.index intrinsics

Use the elementtype attribute introduced in D105407 for the
llvm.preserve.array/struct.index intrinsics. It carries the
element type of the GEP these intrinsics effectively encode.

This patch:

 * Adds a verifier check that the attribute is required.
 * Adds it in the IRBuilder methods for these intrinsics.
 * Autoupgrades old bitcode without the attribute.
 * Updates the lowering code to use the attribute rather than
   the pointer element type.
 * Updates lots of tests to specify the attribute.
 * Adds -force-opaque-pointers to the intrinsic-array.ll test
   to demonstrate they work now.

https://reviews.llvm.org/D106184

1 files changed, 4 insertions, 0 deletions

diff --git a/llvm/lib/IR/Attributes.cpp b/llvm/lib/IR/Attributes.cpp
index 4ef61c7..fc05f52 100644
--- a/llvm/lib/IR/Attributes.cpp
+++ b/llvm/lib/IR/Attributes.cpp
@@ -1467,6 +1467,10 @@ Type *AttributeList::getParamInAllocaType(unsigned Index) const {
   return getAttributes(Index + FirstArgIndex).getInAllocaType();
 }
 
+Type *AttributeList::getParamElementType(unsigned Index) const {
+  return getAttributes(Index + FirstArgIndex).getElementType();
+}
+
 MaybeAlign AttributeList::getStackAlignment(unsigned Index) const {
   return getAttributes(Index).getStackAlignment();
 }