Temporarily revert "Reapply [LVI] Normalize pointer behavior" and "[LVI] Restructure caching"

This reverts commits 7e18aeba5062cd4324a9efb7bc25c9dbc4a34c2c (D70376) 21fbd5587cdfa11dabb3aeb0ead2d3d5fd0b490d (D69914) due to increased memory usage.
diff --git a/llvm/test/Transforms/JumpThreading/combine-metadata.ll b/llvm/test/Transforms/JumpThreading/combine-metadata.ll
index d7c390e..6351236 100644
--- a/llvm/test/Transforms/JumpThreading/combine-metadata.ll
+++ b/llvm/test/Transforms/JumpThreading/combine-metadata.ll
@@ -108,7 +108,7 @@
 d3:
   %y = load i32*, i32** %ptr
   store i32 1, i32* %y
-  %c2 = icmp eq i32* %y, @p
+  %c2 = icmp eq i32* %y, null
   br i1 %c2, label %ret1, label %ret2
 
 ret1:
@@ -118,6 +118,5 @@
   ret void
 }
 
-@p = external global i32
 
 !0 = !{}