[debugserver] Fix sign comparison warning.

Summary:
Comparing m_page_size against kInvalidPageSize was resulting in
a warning about comparing integers with different signs. Since
kInvalidPageSize isn't used anywhere outside of MachVMMemory.cpp,
we can readily transform it into a static const vm_size_t with
the correct value to avoid the sign comparison warnings.

Reviewers: clayborg

Subscribers: lldb-commits

Differential Revision: http://reviews.llvm.org/D12519

llvm-svn: 246606

lldb/tools/debugserver/source/MacOSX/MachVMMemory.cpp

@@ -19,6 +19,8 @@
 #include <sys/sysctl.h>
 #include <dlfcn.h>
 
+static const vm_size_t kInvalidPageSize = ~0;
+
 MachVMMemory::MachVMMemory() :
     m_page_size    (kInvalidPageSize),
     m_err        (0)

lldb/tools/debugserver/source/MacOSX/MachVMMemory.h

@@ -21,7 +21,6 @@
 class MachVMMemory
 {
 public:
-    enum { kInvalidPageSize = ~0 };
     MachVMMemory();
     ~MachVMMemory();
     nub_size_t Read(task_t task, nub_addr_t address, void *data, nub_size_t data_count);