Fix various issues (or do cleanups) found by enabling certain MSVC warnings.

- Use unsigned literals when the desired result is unsigned. This mostly allows unsigned/signed mismatch warnings to be less noisy even if they aren't on by default.
- Remove misplaced llvm_unreachable.
- Add static to a declaration of a function on MSVC x86 only.
- Change some instances of calling a static function through a variable to simply calling that function while removing the unused variable.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@150364 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86JITInfo.cpp b/lib/Target/X86/X86JITInfo.cpp
index 29b623e..0168d12 100644
--- a/lib/Target/X86/X86JITInfo.cpp
+++ b/lib/Target/X86/X86JITInfo.cpp
@@ -300,7 +300,10 @@
     SIZE(X86CompilationCallback_SSE)
   );
 # else
-  void X86CompilationCallback2(intptr_t *StackPtr, intptr_t RetAddr);
+  // the following function is called only from this translation unit,
+  // unless we are under 64bit Windows with MSC, where there is
+  // no support for inline assembly
+  static void X86CompilationCallback2(intptr_t *StackPtr, intptr_t RetAddr);
 
   _declspec(naked) void X86CompilationCallback(void) {
     __asm {