tests: avoid spurious pic_flag test failure on HP-UX 10.20.

[Ralf Wildenhues]

http://autobuild.josefsson.org/libtool/log-201008291316745734000.txt

| 113. pic_flag.at:24: testing override pic_flag at configure time ...
| ../../libtool/tests/pic_flag.at:36: $CC $CPPFLAGS $CFLAGS $C_pic_flag -c 
foo.c || exit 77
| stderr:
| cc: warning 422: Unknown option "f" ignored.
| cc: warning 422: Unknown option "i" ignored.
| stdout:
| ../../libtool/tests/pic_flag.at:39: grep fpic stdout stderr && exit 77

So, let's please this compiler, too.  Pushed.

Cheers,
Ralf

    tests: avoid spurious pic_flag test failure on HP-UX 10.20.
    
    * tests/pic_flag.at (override pic_flag at configure time):
    Match HP-UX 10.20 cc warning about unknown options, to skip
    the test.

diff --git a/tests/pic_flag.at b/tests/pic_flag.at
index ffad842..fb39f7f 100644
--- a/tests/pic_flag.at
+++ b/tests/pic_flag.at
@@ -37,6 +37,7 @@ AT_CHECK([$CC $CPPFLAGS $CFLAGS $C_pic_flag -c foo.c || exit 
77],
         [], [stdout], [stderr])
 # The configure test for the PIC flag also checks for warnings.
 AT_CHECK([grep fpic stdout stderr && exit 77], [1])
+AT_CHECK([[grep '[uU]nknown.*option' stdout stderr && exit 77]], [1])
 
 CXX_pic_flag='-fpic -DPIC'
 if $CXX $CPPFLAGS $CXXFLAGS $CXX_pic_flag -c foo.cpp; then :; else