Revert "Fix warning: comparison of integers of different signs"

This reverts commit 028df7fa.

I am reverting this patch because I need to revert 171f7024 and without reverting this patch, reverting 171f7024 causes conflicts.

 Patch 171f7024 introduced a cyclic dependancy in the module build.

    https://green.lab.llvm.org/green/view/LLDB/job/lldb-cmake/48197/consoleFull#-69937453049ba4694-19c4-4d7e-bec5-911270d8a58c

    In file included from <module-includes>:1:
    /Users/buildslave/jenkins/workspace/lldb-cmake/llvm-project/llvm/include/llvm/IR/Argument.h:18:10: fatal error: cyclic dependency in module 'LLVM_IR': LLVM_IR -> LLVM_intrinsic_gen -> LLVM_IR
             ^
    While building module 'LLVM_MC' imported from /Users/buildslave/jenkins/workspace/lldb-cmake/llvm-project/llvm/lib/MC/MCAsmInfoCOFF.cpp:14:
    While building module 'LLVM_IR' imported from /Users/buildslave/jenkins/workspace/lldb-cmake/llvm-project/llvm/include/llvm/MC/MCPseudoProbe.h:57:
    In file included from <module-includes>:12:
    /Users/buildslave/jenkins/workspace/lldb-cmake/llvm-project/llvm/include/llvm/IR/DebugInfo.h:24:10: fatal error: could not build module 'LLVM_intrinsic_gen'
     ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
    While building module 'LLVM_MC' imported from /Users/buildslave/jenkins/workspace/lldb-cmake/llvm-project/llvm/lib/MC/MCAsmInfoCOFF.cpp:14:
    In file included from <module-includes>:15:
    In file included from /Users/buildslave/jenkins/workspace/lldb-cmake/llvm-project/llvm/include/llvm/MC/MCContext.h:23:
    /Users/buildslave/jenkins/workspace/lldb-cmake/llvm-project/llvm/include/llvm/MC/MCPseudoProbe.h:57:10: fatal error: could not build module 'LLVM_IR'
     ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
    /Users/buildslave/jenkins/workspace/lldb-cmake/llvm-project/llvm/lib/MC/MCAsmInfoCOFF.cpp:14:10: fatal error: could not build module 'LLVM_MC'
     ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
    4 errors generated.