Store and emit original name in combined index

Summary:
As discussed in D18298, some local globals can't
be renamed/promoted (because they have a section, or because
they are referenced from inline assembly).
To be able to detect naming collision, we need to keep around
the "GUID" using their original name without taking the linkage
into account.

Reviewers: tejohnson

Subscribers: joker.eph, llvm-commits

Differential Revision: http://reviews.llvm.org/D19454

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 267304

llvm/test/Bitcode/thinlto-function-summary-originalnames.ll

@@ -0,0 +1,24 @@
+; Test to check the callgraph in summary
+; RUN: opt -module-summary %s -o %t.o
+; RUN: llvm-lto -thinlto-action=thinlink -o %t.index.bc %t.o
+; RUN: llvm-bcanalyzer -dump %t.index.bc | FileCheck %s --check-prefix=COMBINED
+
+; COMBINED:       <GLOBALVAL_SUMMARY_BLOCK
+; COMBINED-NEXT:    <COMBINED
+; COMBINED-NEXT:    <COMBINED_ORIGINAL_NAME op0=6699318081062747564/>
+; COMBINED-NEXT:    <COMBINED_GLOBALVAR_INIT_REFS
+; COMBINED-NEXT:    <COMBINED_ORIGINAL_NAME op0=-2012135647395072713/>
+; COMBINED-NEXT:    <COMBINED_ALIAS
+; COMBINED-NEXT:    <COMBINED_ORIGINAL_NAME op0=-4170563161550796836/>
+; COMBINED-NEXT:  </GLOBALVAL_SUMMARY_BLOCK>
+
+; ModuleID = 'thinlto-function-summary-callgraph.ll'
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+@bar = internal global i32 0
+@fooalias = internal alias void (...), bitcast (void ()* @foo to void (...)*)
+
+define internal void @foo() {
+    ret void
+}