[PATCH v2 1/4] tools/tests/x86_emulator: avoid duplicate symbol error with clang

[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
```

Avoid this by only emitting the symbols surrounding the instructions if
they are not already defined. (We know that the definitions would be
identical, and we only need one of them as input to the emulator)

Signed-off-by: Edwin Török <edwin.torok@xxxxxxxxxx>
---
Changed since v1:
 * use .ifndef directive instead of volatile workaround
---
 tools/tests/x86_emulator/test_x86_emulator.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/tools/tests/x86_emulator/test_x86_emulator.c 
b/tools/tests/x86_emulator/test_x86_emulator.c
index ea507f9c3a..8f93a8bbcd 100644
--- a/tools/tests/x86_emulator/test_x86_emulator.c
+++ b/tools/tests/x86_emulator/test_x86_emulator.c
@@ -1882,8 +1882,13 @@ int main(int argc, char **argv)
 #define decl_insn(which) extern const unsigned char which[], \
                          which##_end[] asm ( ".L" #which "_end" )
 #define put_insn(which, insn) ".pushsection .test\n" \
-                              #which ": " insn "\n"  \
+                              ".ifndef "#which"\n" \
+                              #which ": \n" \
+                              ".endif\n" \
+                              insn "\n"  \
+                              ".ifndef .L"#which"_end\n" \
                               ".L" #which "_end:\n"  \
+                              ".endif\n" \
                               ".popsection"
 #define set_insn(which) (regs.eip = (unsigned long)(which))
 #define valid_eip(which) (regs.eip >= (unsigned long)(which) && \
@@ -5248,7 +5253,7 @@ 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 (i = 0; i < 2; ++i )
         {
             decl_insn(vmovsh_to_mem);
 
-- 
2.47.3