Null initialize a few variables flagged by
clang's -Wuninitialized-experimental warning.
While these don't look like real bugs, clang's
-Wuninitialized-experimental analysis is stricter
than GCC's, and these fixes have the benefit
of being general nice cleanups.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124073 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/Disassembler/X86DisassemblerDecoder.c b/lib/Target/X86/Disassembler/X86DisassemblerDecoder.c
index 0af510c..7b17f1e 100644
--- a/lib/Target/X86/Disassembler/X86DisassemblerDecoder.c
+++ b/lib/Target/X86/Disassembler/X86DisassemblerDecoder.c
@@ -290,7 +290,7 @@
   BOOL isPrefix = TRUE;
   BOOL prefixGroups[4] = { FALSE };
   uint64_t prefixLocation;
-  uint8_t byte;
+  uint8_t byte = 0;
   
   BOOL hasAdSize = FALSE;
   BOOL hasOpSize = FALSE;