[SVE][IR] Scalable Vector size queries and IR instruction support

* Adds a TypeSize struct to represent the known minimum size of a type
  along with a flag to indicate that the runtime size is a integer multiple
  of that size
* Converts existing size query functions from Type.h and DataLayout.h to
  return a TypeSize result
* Adds convenience methods (including a transparent conversion operator
  to uint64_t) so that most existing code 'just works' as if the return
  values were still scalars.
* Uses the new size queries along with ElementCount to ensure that all
  supported instructions used with scalable vectors can be constructed
  in IR.

Reviewers: hfinkel, lattner, rkruppe, greened, rovka, rengolin, sdesmalen

Reviewed By: rovka, sdesmalen

Differential Revision: https://reviews.llvm.org/D53137

llvm-svn: 374042
diff --git a/clang/lib/CodeGen/CGCall.cpp b/clang/lib/CodeGen/CGCall.cpp
index e851d7b..b016b46 100644
--- a/clang/lib/CodeGen/CGCall.cpp
+++ b/clang/lib/CodeGen/CGCall.cpp
@@ -4277,8 +4277,8 @@
   // Update the largest vector width if any arguments have vector types.
   for (unsigned i = 0; i < IRCallArgs.size(); ++i) {
     if (auto *VT = dyn_cast<llvm::VectorType>(IRCallArgs[i]->getType()))
-      LargestVectorWidth = std::max(LargestVectorWidth,
-                                    VT->getPrimitiveSizeInBits());
+      LargestVectorWidth = std::max((uint64_t)LargestVectorWidth,
+                                   VT->getPrimitiveSizeInBits().getFixedSize());
   }
 
   // Compute the calling convention and attributes.
@@ -4361,8 +4361,8 @@
 
   // Update largest vector width from the return type.
   if (auto *VT = dyn_cast<llvm::VectorType>(CI->getType()))
-    LargestVectorWidth = std::max(LargestVectorWidth,
-                                  VT->getPrimitiveSizeInBits());
+    LargestVectorWidth = std::max((uint64_t)LargestVectorWidth,
+                                  VT->getPrimitiveSizeInBits().getFixedSize());
 
   // Insert instrumentation or attach profile metadata at indirect call sites.
   // For more details, see the comment before the definition of