Suppress i386-avx tests for the same reason as all the other register tests

This just hadn't been hit because I hadn't run the test suite on hardware that supported AVX.

llvm-svn: 211179
diff --git a/clang-tests-external/gdb/7.5/gdb/testsuite/gdb.arch/i386-avx.exp b/clang-tests-external/gdb/7.5/gdb/testsuite/gdb.arch/i386-avx.exp
index 52a6e4a..96de3e6 100644
--- a/clang-tests-external/gdb/7.5/gdb/testsuite/gdb.arch/i386-avx.exp
+++ b/clang-tests-external/gdb/7.5/gdb/testsuite/gdb.arch/i386-avx.exp
@@ -24,6 +24,11 @@
     return
 }
 
+if [using_clang] {
+    unsupported "test is oversensitive to register allocation/unoptimized code"
+    return -1
+}
+
 set testfile "i386-avx"
 set srcfile ${testfile}.c
 set binfile ${objdir}/${subdir}/${testfile}