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)
diff --git a/lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp b/lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp
index 814df88..84e3ddd 100644
--- a/lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp
+++ b/lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp
@@ -4646,7 +4646,7 @@
 
         Error err;
         uint32_t version_or_magic = process->ReadUnsignedIntegerFromMemory (all_image_infos, 4, -1, err);
-        if (version_or_magic != -1 
+        if (version_or_magic != static_cast<uint32_t>(-1)
             && version_or_magic != MH_MAGIC
             && version_or_magic != MH_CIGAM
             && version_or_magic != MH_MAGIC_64