Add support for subsections to the ELF assembler. Fixes PR8717.

Differential Revision: http://llvm-reviews.chandlerc.com/D598

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179725 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/MC/MCSectionCOFF.cpp b/lib/MC/MCSectionCOFF.cpp
index aac9377..6cedf06 100644
--- a/lib/MC/MCSectionCOFF.cpp
+++ b/lib/MC/MCSectionCOFF.cpp
@@ -29,7 +29,8 @@
 }
 
 void MCSectionCOFF::PrintSwitchToSection(const MCAsmInfo &MAI,
-                                         raw_ostream &OS) const {
+                                         raw_ostream &OS,
+                                         const MCExpr *Subsection) const {
 
   // standard sections don't require the '.section'
   if (ShouldOmitSectionDirective(SectionName, MAI)) {