[Draft] add func map section header

[wlei-llvm]

Test Plan: llvm/test/CodeGen/X86/function-address-map-function-sections.ll

[github-actions]

⚠️ C/C++ code formatter, clang-format found issues in your code. ⚠️

You can test this locally with the following command:

git-clang-format --diff 7d4830352bc089cbc82043c6365821f9c1e7f2b6 b5edcb2abe2e7c0d6869d15e947f01630b66adb3 --extensions cpp,h -- llvm/include/llvm/CodeGen/AsmPrinter.h llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp

View the diff from clang-format here.

diff --git a/llvm/include/llvm/CodeGen/AsmPrinter.h b/llvm/include/llvm/CodeGen/AsmPrinter.h
index b58c02763a..bec6df60a6 100644
--- a/llvm/include/llvm/CodeGen/AsmPrinter.h
+++ b/llvm/include/llvm/CodeGen/AsmPrinter.h
@@ -418,7 +418,7 @@ public:
   void emitBBAddrMapSection(const MachineFunction &MF);
 
   void emitFuncMapStart();
-  
+
   void emitFuncMapEnd();
 
   void emitFuncMapSection(const MachineFunction &MF);