configure.ac: Do not assume gcc strength reduce bug when crosscompiling.

[Sebastian Lackner]

Clang does not support '-fno-strength-reduce' and will print the following
error messages for each compiled file:

clang: warning: optimization flag '-fno-strength-reduce' is not supported
clang: warning: argument unused during compilation: '-fno-strength-reduce'

This was bug was fixed in gcc-2.7.2.1 which was released 19 years ago,
so its probably safe to assume that its not present when crosscompiling.

---
 configure.ac |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/configure.ac b/configure.ac
index 3eaec29..9aab130 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1797,7 +1797,7 @@ then
   for(i=0; i<4 - 1; i++) L[[i]] = L[[i + 1]];
   L[[i]] = 4;
   return (Array[[1]] != -2 || L[[2]] != 3)]])],
-    [ac_cv_c_gcc_strength_bug="no"],[ac_cv_c_gcc_strength_bug="yes"],[ac_cv_c_gcc_strength_bug="yes"]) )
+    [ac_cv_c_gcc_strength_bug="no"],[ac_cv_c_gcc_strength_bug="yes"],[ac_cv_c_gcc_strength_bug="no"]) )
   if test "$ac_cv_c_gcc_strength_bug" = "yes"
   then
     EXTRACFLAGS="$EXTRACFLAGS -fno-strength-reduce"
-- 
2.4.5