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/MCSectionMachO.cpp b/lib/MC/MCSectionMachO.cpp
index fc32315..8704513 100644
--- a/lib/MC/MCSectionMachO.cpp
+++ b/lib/MC/MCSectionMachO.cpp
@@ -91,7 +91,8 @@
 }
 
 void MCSectionMachO::PrintSwitchToSection(const MCAsmInfo &MAI,
-                                          raw_ostream &OS) const {
+                                          raw_ostream &OS,
+                                          const MCExpr *Subsection) const {
   OS << "\t.section\t" << getSegmentName() << ',' << getSectionName();
 
   // Get the section type and attributes.