Fix LLVM trunk build

ld: error: duplicate symbol: dis_info
>>> defined at i386_disasm.c:1665
>>>            otool-i386_disasm.o:(dis_info)
>>> defined at arm_disasm.c:163
>>>            otool-arm_disasm.o:(.bss+0x8)

ld: error: duplicate symbol: dis_info
>>> defined at i386_disasm.c:1665
>>>            otool-i386_disasm.o:(dis_info)
>>> defined at arm64_disasm.c:62
>>>            otool-arm64_disasm.o:(.bss+0x0)
clang-11: error: linker command failed with exit code 1 (use -v to see invocation)

cctools/otool/arm64_disasm.c

@@ -16,6 +16,7 @@
 #include "arm64_disasm.h"
 #include "cxa_demangle.h"
 
+static /* cctools-port */
 struct disassemble_info {
   /* otool(1) specific stuff */
   enum bool verbose;

cctools/otool/arm_disasm.c

@@ -64,6 +64,7 @@ typedef char bfd_byte;
 
 /* HACKS to avoid pulling in all of FSF binutils include/dis-asm.h */
 typedef int (*fprintf_ftype) (void *, const char*, ...);
+static /* cctools-port */
 struct disassemble_info { /* HACK'ed up for just what we need here */
   fprintf_ftype fprintf_func;
   void *stream;

cctools/otool/i386_disasm.c

@@ -1618,6 +1618,7 @@ static unsigned int xmm_rm(int r_m, int rex)
 /*
  * This is passed to the llvm disassembler.
  */
+static /* cctools-port */
 struct disassemble_info {
   enum bool verbose;
   /* Relocation information.  */