[DebugInfo][test] Fix llvm/test/ThinLTO/X86/pr35472.ll (NFC) (#170952)

The test is intended to verify lazy loading of debug-location scope
metadata. However, after d5d3eb1,
DILexicalScope that was expected to be lazily loaded was not used in IR,
so lazy loading did not occur.

This patch fixes that, and adds an extra bcanalyzer check to ensure that
DILexicalScope record is emitted.

Author: dzhidzhoev

llvm/test/ThinLTO/X86/pr35472.ll

@@ -8,11 +8,35 @@
 ; RUN: llvm-lto -thinlto-action=run %t1.bc %t2.bc -exported-symbol=_Z5Alphav
 ; RUN: llvm-nm %t1.bc.thinlto.o | FileCheck %s -check-prefix=ThinLTOa
 ; RUN: llvm-nm %t2.bc.thinlto.o | FileCheck %s -check-prefix=ThinLTOb
+; RUN: llvm-bcanalyzer -dump %t1.bc | FileCheck %s --implicit-check-not='<METADATA_BLOCK'
 
 ; ThinLTOa-DAG: T _Z5Bravov
 ; ThinLTOa-DAG: W _ZN4EchoD2Ev
 ; ThinLTOb-DAG: T _Z5Alphav
 
+; Make sure that lexical block was emitted into the module level metadata block,
+; and that metadata index for the module level metadata block is present, as it
+; is necessary to trigger lazy loading.
+; CHECK:  <MODULE_BLOCK
+; CHECK:      <METADATA_BLOCK
+; CHECK:      <INDEX_OFFSET
+; CHECK:      <LEXICAL_BLOCK
+; CHECK:      <INDEX
+; CHECK:    </METADATA_BLOCK>
+; CHECK:    <FUNCTION_BLOCK
+; CHECK:      <METADATA_BLOCK
+; CHECK:      </METADATA_BLOCK>
+; CHECK:    </FUNCTION_BLOCK
+; CHECK:    <FUNCTION_BLOCK
+; CHECK:      <METADATA_BLOCK
+; CHECK:      </METADATA_BLOCK>
+; CHECK:    </FUNCTION_BLOCK
+; CHECK:    <FUNCTION_BLOCK
+; CHECK:      <METADATA_BLOCK
+; CHECK:      </METADATA_BLOCK>
+; CHECK:    </FUNCTION_BLOCK
+; CHECK: </MODULE_BLOCK
+
 target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
 target triple = "x86_64-unknown-linux-gnu"
 
@@ -36,14 +60,14 @@ declare void @llvm.dbg.declare(metadata, metadata, metadata)
 define linkonce_odr void @_ZN4EchoD2Ev(ptr %this) unnamed_addr comdat align 2 {
   %this.addr.i = alloca ptr, align 8
   call void @llvm.dbg.declare(metadata ptr %this.addr.i, metadata !29, metadata !DIExpression()), !dbg !32
-  %this1.i = load ptr, ptr %this.addr.i, align 8
+  %this1.i = load ptr, ptr %this.addr.i, align 8, !dbg !33
   ret void
 }
 
 define linkonce_odr void @_ZN5DeltaD2Ev(ptr %this) unnamed_addr comdat align 2 !dbg !36 {
   %this.addr.i = alloca ptr, align 8
   call void @llvm.dbg.declare(metadata ptr %this.addr.i, metadata !29, metadata !DIExpression()), !dbg !41
-  %this1.i = load ptr, ptr %this.addr.i, align 8
+  %this1.i = load ptr, ptr %this.addr.i, align 8, !dbg !48
   ret void
 }