[EH] Rename llvm.x86.seh.recoverfp intrinsic to llvm.eh.recoverfp

Summary:
Make recoverfp intrinsic target-independent so that it can be implemented for AArch64, etc.
Refer D53541 for the context. Clang counterpart D56748.

Reviewers: rnk, efriedma

Reviewed By: rnk, efriedma

Subscribers: javed.absar, kristof.beyls, llvm-commits

Differential Revision: https://reviews.llvm.org/D56747

llvm-svn: 351281
diff --git a/llvm/lib/IR/AutoUpgrade.cpp b/llvm/lib/IR/AutoUpgrade.cpp
index a00cab8..b2eb8b0 100644
--- a/llvm/lib/IR/AutoUpgrade.cpp
+++ b/llvm/lib/IR/AutoUpgrade.cpp
@@ -544,6 +544,10 @@
       NewFn = Intrinsic::getDeclaration(F->getParent(), Intrinsic::thread_pointer);
       return true;
     }
+    if (Name == "x86.seh.recoverfp") {
+      NewFn = Intrinsic::getDeclaration(F->getParent(), Intrinsic::eh_recoverfp);
+      return true;
+    }
     break;
   }