sanitise sign comparisons

This is a mechanical change addressing the various sign comparison warnings that
are identified by both clang and gcc.  This helps cleanup some of the warning
spew that occurs during builds.

llvm-svn: 205390
diff --git a/lldb/source/Plugins/ObjectFile/JIT/ObjectFileJIT.cpp b/lldb/source/Plugins/ObjectFile/JIT/ObjectFileJIT.cpp
index 530e11a..ec0f093 100644
--- a/lldb/source/Plugins/ObjectFile/JIT/ObjectFileJIT.cpp
+++ b/lldb/source/Plugins/ObjectFile/JIT/ObjectFileJIT.cpp
@@ -329,7 +329,7 @@
                                 size_t dst_len) const
 {
     lldb::offset_t file_size = section->GetFileSize();
-    if (section_offset < file_size)
+    if (section_offset < static_cast<off_t>(file_size))
     {
         uint64_t src_len = file_size - section_offset;
         if (src_len > dst_len)