MachO,test: Test DWARF section's begin symbol
MCObjectFileInfo::initMachOMCObjectFileInfo creates DWARF sections with
a temporary label as the `Begin` symbol, different from other object
file formats' section symbol.
#150574 caused a regression that removed the label for MCAsmStreamer,
which was caught by no test but a ystem-darwin/target-aarch64 specific diagnostics-dsym.test
diff --git a/llvm/test/DebugInfo/X86/stringpool.ll b/llvm/test/DebugInfo/X86/stringpool.ll
index 219e672..1c3a57a 100644
--- a/llvm/test/DebugInfo/X86/stringpool.ll
+++ b/llvm/test/DebugInfo/X86/stringpool.ll
@@ -28,8 +28,12 @@
; LINUX: .section .debug_str,"MS",@progbits,1
; LINUX: yyyy
+; DARWIN: .section __DWARF,__debug_abbrev,regular,debug
+; DARWIN-NEXT: Lsection_abbrev:
+
; Verify that we refer to 'yyyy' with a direct offset.
; DARWIN: .section __DWARF,__debug_info,regular,debug
+; DARWIN: Lset1 = Lsection_abbrev-Lsection_abbrev
; DARWIN: DW_TAG_variable
; DARWIN: .long [[YYYY:[0-9]+]]
; DARWIN-NEXT: .long {{[0-9]+}} ## DW_AT_type
