[MC] Remove comment no longer useful

[brad]

Summary

Remove a comment block regarding IAS. The comment is out of sync with the current status and I don't think such a comment block is necessary anymore.

[MaskRay]

Looks great!

llvm/lib/MC/MCAsmInfo.cpp

MCAsmInfo::MCAsmInfo() {
   Data32bitsDirective = "\t.long\t";
   Data64bitsDirective = "\t.quad\t";
   GlobalDirective = "\t.globl\t";
   WeakDirective = "\t.weak\t";
   if (DwarfExtendedLoc != Default)
     SupportsExtendedDwarfLocDirective = DwarfExtendedLoc == Enable;
   if (UseLEB128Directives != cl::BOU_UNSET)
     HasLEB128Directives = UseLEB128Directives == cl::BOU_TRUE;
-
-  // FIXME: Clang's logic should be synced with the logic used to initialize
-  //        this member and the two implementations should be merged.
-  // For reference:
-  // - Solaris always enables the integrated assembler by default
-  //   - SparcELFMCAsmInfo and X86ELFMCAsmInfo are handling this case
-  // - Windows always enables the integrated assembler by default
-  //   - MCAsmInfoCOFF is handling this case, should it be MCAsmInfoMicrosoft?
-  // - MachO targets always enables the integrated assembler by default
-  //   - MCAsmInfoDarwin is handling this case
-  // - Generic_GCC toolchains enable the integrated assembler on a per
-  //   architecture basis.
-  //   - The target subclasses for AArch64, ARM, and X86 handle these cases
   UseIntegratedAssembler = true;
   ParseInlineAsmUsingAsmParser = false;
   PreserveAsmComments = true;
 }
 
 MCAsmInfo::~MCAsmInfo() = default;
 
 void MCAsmInfo::addInitialFrameState(const MCCFIInstruction &Inst) {