[ThinLTO] Add FunctionAttrs to ThinLTO index

Adds function attributes to index: ReadNone, ReadOnly, NoRecurse, NoAlias. This attributes will be used for future ThinLTO optimizations that will propagate function attributes across modules.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@310061 91177308-0d34-0410-b5e6-96231b3b80d8

test/Bitcode/thinlto-function-summary-functionattrs.ll

@@ -0,0 +1,27 @@
+; RUN: opt -module-summary %s -o %t.o
+; RUN: llvm-bcanalyzer -dump %t.o | FileCheck %s
+
+; CHECK: <GLOBALVAL_SUMMARY_BLOCK
+; ensure @f is marked readnone
+; CHECK:  <PERMODULE {{.*}} op0=0 {{.*}} op3=1
+; ensure @g is marked readonly
+; CHECK:  <PERMODULE {{.*}} op0=1 {{.*}} op3=2
+; ensure @h is marked norecurse
+; CHECK:  <PERMODULE {{.*}} op0=2 {{.*}} op3=4
+; ensure @i is marked returndoesnotalias
+; CHECK:  <PERMODULE {{.*}} op0=3 {{.*}} op3=8
+
+define void @f() readnone {
+   ret void
+}
+define void @g() readonly {
+   ret void
+}
+define void @h() norecurse {
+   ret void
+}
+
+define noalias i8* @i() {
+   %r = alloca i8
+   ret i8* %r
+}