[PATCH 2/4] tools/tests/x86_emulator: avoid duplicating loop body

[Edwin Török <edwin.torok@xxxxxxxxxx>]

clang would duplicate the loop body and end up with a double definition
of the symbol:
```
/tmp/test_x86_emulator-0f3576.s:27823: Error: symbol `vmovsh_to_mem' is already 
defined
/tmp/test_x86_emulator-0f3576.s:27825: Error: symbol `.Lvmovsh_to_mem_end' is 
already defined
```

This is a valid transformation, that even GCC might do, see
https://gcc.gnu.org/onlinedocs/gcc/Extended-Asm.html#Volatile-1 which
says that `%=` should be used instead. However the C code here also
needs to know the name of the label, so I don't immediately see how to
solve that.

For now mark the loop variable `volatile` to prevent the optimization as a
workaround.
(another way to fix this could be to move the loop body into a function,
but a compiler might inline it, or specialize it, leading to the same problem)

Signed-off-by: Edwin Török <edwin.torok@xxxxxxxxxx>
---
 tools/tests/x86_emulator/test_x86_emulator.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/tests/x86_emulator/test_x86_emulator.c 
b/tools/tests/x86_emulator/test_x86_emulator.c
index a25eca1634..cf4e5cc593 100644
--- a/tools/tests/x86_emulator/test_x86_emulator.c
+++ b/tools/tests/x86_emulator/test_x86_emulator.c
@@ -5248,7 +5248,7 @@ int main(int argc, char **argv)
         memset(res + 3, ~0, 8);
         regs.eax = (unsigned long)res;
         regs.ecx = ~0;
-        for ( i = 0; i < 2; ++i )
+        for (volatile int i = 0; i < 2; ++i )
         {
             decl_insn(vmovsh_to_mem);
 
-- 
2.47.3