Revert "OpaquePtr: Turn inalloca into a type attribute"

This reverts commit 4fefed65637ec46c8c2edad6b07b5569ac61e9e5.
Broke check-clang everywhere.

GitOrigin-RevId: 20d5c42e0ef5d252b434bcb610b04f1cb79fe771
diff --git a/test/Bitcode/inalloca.ll b/test/Bitcode/inalloca.ll
index 3b56f57..84abe17 100644
--- a/test/Bitcode/inalloca.ll
+++ b/test/Bitcode/inalloca.ll
@@ -3,17 +3,17 @@
 
 ; inalloca should roundtrip.
 
-define void @foo(i32* inalloca(i32) %args) {
+define void @foo(i32* inalloca %args) {
   ret void
 }
-; CHECK-LABEL: define void @foo(i32* inalloca(i32) %args)
+; CHECK-LABEL: define void @foo(i32* inalloca %args)
 
 define void @bar() {
   ; Use the maximum alignment, since we stuff our bit with alignment.
   %args = alloca inalloca i32, align 536870912
-  call void @foo(i32* inalloca(i32) %args)
+  call void @foo(i32* inalloca %args)
   ret void
 }
 ; CHECK-LABEL: define void @bar() {
 ; CHECK: %args = alloca inalloca i32, align 536870912
-; CHECK: call void @foo(i32* inalloca(i32) %args)
+; CHECK: call void @foo(i32* inalloca %args)