[NFC]Precommit test for vtable import (#79363)

A precommit test case to show function summary and global values when a function has instructions annotated with vtable profiles and indirect call profiles.
- This is a precommit test for #79381

Author: mingmingl-llvm

llvm/test/Bitcode/thinlto-func-summary-vtableref-pgo.ll

@@ -0,0 +1,61 @@
+; RUN: opt -module-summary %s -o %t.o
+
+; RUN: llvm-bcanalyzer -dump %t.o | FileCheck %s
+
+; RUN: llvm-dis -o - %t.o | FileCheck %s --check-prefix=DIS
+
+
+; CHECK: <GLOBALVAL_SUMMARY_BLOCK
+; CHECK-NEXT:   <VERSION op0=9/>
+; CHECK-NEXT:   <FLAGS op0=0/>
+; The `VALUE_GUID` below represents the "_ZN4Base4funcEv" referenced by the
+; indirect call instruction.
+; CHECK-NEXT:   <VALUE_GUID op0=17 op1=5459407273543877811/>
+; <PERMODULE_PROFILE> has the format [valueid, flags, instcount, funcflags,
+;                                     numrefs, rorefcnt, worefcnt,
+;                                     n x (valueid, hotness+tailcall)]
+; CHECK-NEXT:   <PERMODULE_PROFILE abbrevid=4 op0=0 op1=0 op2=4 op3=256 op4=0 op5=0 op6=0 op7=17 op8=3/>
+; CHECK-NEXT:  </GLOBALVAL_SUMMARY_BLOCK>
+
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+; Function has one BB and an entry count of 150, so the BB is hot according to
+; ProfileSummary and reflected so in the bitcode (see llvm-dis output).
+define i32 @_Z4testP4Base(ptr %0) !prof !15 {
+  %2 = load ptr, ptr %0, !prof !16
+  %3 = load ptr, ptr %2
+  %4 = tail call i32 %3(ptr %0), !prof !17
+  ret i32 %4
+}
+
+!llvm.module.flags = !{!1}
+
+
+!1 = !{i32 1, !"ProfileSummary", !2}
+!2 = !{!3, !4, !5, !6, !7, !8, !9, !10}
+!3 = !{!"ProfileFormat", !"InstrProf"}
+!4 = !{!"TotalCount", i64 10000}
+!5 = !{!"MaxCount", i64 200}
+!6 = !{!"MaxInternalCount", i64 200}
+!7 = !{!"MaxFunctionCount", i64 200}
+!8 = !{!"NumCounts", i64 3}
+!9 = !{!"NumFunctions", i64 3}
+!10 = !{!"DetailedSummary", !11}
+!11 = !{!12, !13, !14}
+!12 = !{i32 10000, i64 100, i32 1}
+!13 = !{i32 990000, i64 100, i32 1}
+!14 = !{i32 999999, i64 1, i32 2}
+
+!15 = !{!"function_entry_count", i32 150}
+; 1960855528937986108 is the MD5 hash of _ZTV4Base
+!16 = !{!"VP", i32 2, i64 1600, i64 1960855528937986108, i64 1600}
+; 5459407273543877811 is the MD5 hash of _ZN4Base4funcEv
+!17 = !{!"VP", i32 0, i64 1600, i64 5459407273543877811, i64 1600}
+
+; ModuleSummaryIndex stores <guid, global-value summary> map in std::map; so
+; global value summares are printed out in the order that gv's guid increases.
+; DIS: ^0 = module: (path: "{{.*}}", hash: (0, 0, 0, 0, 0))
+; DIS: ^1 = gv: (guid: 5459407273543877811)
+; DIS: ^2 = gv: (name: "_Z4testP4Base", summaries: (function: (module: ^0, flags: (linkage: external, visibility: default, notEligibleToImport: 0, live: 0, dsoLocal: 0, canAutoHide: 0), insts: 4, funcFlags: (readNone: 0, readOnly: 0, noRecurse: 0, returnDoesNotAlias: 0, noInline: 0, alwaysInline: 0, noUnwind: 0, mayThrow: 0, hasUnknownCall: 1, mustBeUnreachable: 0), calls: ((callee: ^1, hotness: hot))))) ; guid = 15857150948103218965
+; DIS: ^3 = blockcount: 0