Tentative fix for r351701 and gcc 6.2 build on ubuntu

llvm-svn: 351728

Author: serge-sans-paille-qb

lld/ELF/SyntheticSections.h

@@ -316,8 +316,9 @@ class MipsGotSection final : public SyntheticSection {
     size_t StartIndex = 0;
 
     struct PageBlock {
-      size_t FirstIndex = 0;
-      size_t Count = 0;
+      size_t FirstIndex;
+      size_t Count;
+      PageBlock() : FirstIndex(0), Count(0) {}
     };
 
     // Map output sections referenced by MIPS GOT relocations