[COFF] Set .llvmbc and .llvmcmd to metadata section (llvm#150879)

Those are metadata sections for ELF but was not properly set for COFF.

Author: HaohaiWen

llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp

@@ -1734,7 +1734,8 @@ MCSection *TargetLoweringObjectFileCOFF::getExplicitSectionGlobal(
       Name == getInstrProfSectionName(IPSK_covdata, Triple::COFF,
                                       /*AddSegmentInfo=*/false) ||
       Name == getInstrProfSectionName(IPSK_covname, Triple::COFF,
-                                      /*AddSegmentInfo=*/false))
+                                      /*AddSegmentInfo=*/false) ||
+      Name == ".llvmbc" || Name == ".llvmcmd")
     Kind = SectionKind::getMetadata();
   int Selection = 0;
   unsigned Characteristics = getCOFFSectionFlags(Kind, TM);

llvm/test/CodeGen/X86/embed-bitcode.ll

@@ -1,10 +1,23 @@
 ; RUN: llc -filetype=obj -mtriple=x86_64 %s -o %t
 ; RUN: llvm-readelf -S %t | FileCheck %s
+; RUN: llc -filetype=obj -mtriple=x86_64-pc-windows-msvc %s -o %t
+; RUN: llvm-readobj -S %t | FileCheck %s --check-prefix=COFF
 
 ; CHECK:      .text    PROGBITS 0000000000000000 [[#%x,OFF:]] 000000 00 AX 0
 ; CHECK-NEXT: .llvmbc  PROGBITS 0000000000000000 [[#%x,OFF:]] 000004 00    0
 ; CHECK-NEXT: .llvmcmd PROGBITS 0000000000000000 [[#%x,OFF:]] 000005 00    0
 
+; COFF:      Name: .llvmbc (2E 6C 6C 76 6D 62 63 00)
+; COFF:      Characteristics [
+; COFF-NEXT:   IMAGE_SCN_ALIGN_1BYTES
+; COFF-NEXT:   IMAGE_SCN_MEM_DISCARDABLE
+; COFF-NEXT: ]
+; COFF:      Name: .llvmcmd (2E 6C 6C 76 6D 63 6D 64)
+; COFF:      Characteristics [
+; COFF-NEXT:   IMAGE_SCN_ALIGN_1BYTES
+; COFF-NEXT:   IMAGE_SCN_MEM_DISCARDABLE
+; COFF-NEXT: ]
+
 @llvm.embedded.module = private constant [4 x i8] c"BC\C0\DE", section ".llvmbc", align 1
 @llvm.cmdline = private constant [5 x i8] c"-cc1\00", section ".llvmcmd", align 1
 @llvm.compiler.used = appending global [2 x ptr] [ptr @llvm.embedded.module, ptr @llvm.cmdline], section "llvm.metadata"