[dsymutil] Fix __LINKEDIT vmsize in dsymutil upgrade path

Summary:
dsymutil upgrade path can change the size of segment and it needs to update
the vmsize of the segment to reflect the size change.

rdar://problem/30290714

Reviewers: friss

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D29433

llvm-svn: 293842

llvm/tools/dsymutil/MachOUtils.cpp

@@ -236,6 +236,8 @@ static void transferSegmentAndSections(
   if (StringRef("__LINKEDIT") == Segment.segname) {
     Segment.fileoff = LinkeditOffset;
     Segment.filesize = LinkeditSize;
+    // Resize vmsize by rounding to the page size.
+    Segment.vmsize = alignTo(LinkeditSize, 0x1000);
   }
 
   // Check if the end address of the last segment and our current