Use a bitfield. NFC.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238705 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/MC/MCSection.h

@@ -73,7 +73,7 @@ private:
 
   /// \brief We've seen a bundle_lock directive but not its first instruction
   /// yet.
-  bool BundleGroupBeforeFirstInst = false;
+  unsigned BundleGroupBeforeFirstInst : 1;
 
   /// Whether this section has had instructions emitted into it.
   unsigned HasInstructions : 1;

lib/MC/MCSection.cpp

@@ -20,7 +20,8 @@ using namespace llvm;
 //===----------------------------------------------------------------------===//
 
 MCSection::MCSection(SectionVariant V, SectionKind K, MCSymbol *Begin)
-    : Begin(Begin), HasInstructions(false), Variant(V), Kind(K) {}
+    : Begin(Begin), BundleGroupBeforeFirstInst(false), HasInstructions(false),
+      Variant(V), Kind(K) {}
 
 MCSymbol *MCSection::getEndSymbol(MCContext &Ctx) {
   if (!End)