PATCH: silence build warning from libstdc++

[Ben Elliston]

When building libstdc++, I see (paths trimmed for brevity):

stdtr1c++.h:29: warning: include/powerpc-linux/bits/stdc++.h.gch/O2ggnu++0x.gch: not used because `__GXX_EXPERIMENTAL_CXX0X__' not defined

I propose the following patch to fix this (unless anyone can suggest a
better way?).  Okay for mainline?

Thanks, Ben


2009-04-28  Ben Elliston  <bje@au.ibm.com>

        * include/Makefile.am (${pch2_output}): Add -Wno-invalid-pch.
        * include/Makefile.in: Regenerate.

Index: include/Makefile.am
===================================================================
--- include/Makefile.am (revision 146873)
+++ include/Makefile.am (working copy)
@@ -1109,7 +1109,7 @@
 # Build a precompiled TR1 include, stdtr1c++.h.gch/O2.gch
 ${pch2_output}: ${pch2_source} ${pch1_output}
        -mkdir -p ${pch2_output_builddir}
-       $(CXX) $(PCHFLAGS) $(AM_CPPFLAGS) -O2 -g ${pch2_source} -o $@
+       $(CXX) $(PCHFLAGS) -Wno-invalid-pch $(AM_CPPFLAGS) -O2 -g ${pch2_source} -o $@
 
 # Build a precompiled extension include, extc++.h.gch/O2.gch
 ${pch3_output}: ${pch3_source} ${pch2_output}
Index: include/Makefile.in
===================================================================
--- include/Makefile.in (revision 146873)
+++ include/Makefile.in (working copy)
@@ -1513,7 +1513,7 @@
 # Build a precompiled TR1 include, stdtr1c++.h.gch/O2.gch
 ${pch2_output}: ${pch2_source} ${pch1_output}
        -mkdir -p ${pch2_output_builddir}
-       $(CXX) $(PCHFLAGS) $(AM_CPPFLAGS) -O2 -g ${pch2_source} -o $@
+       $(CXX) $(PCHFLAGS) -Wno-invalid-pch $(AM_CPPFLAGS) -O2 -g ${pch2_source} -o $@
 
 # Build a precompiled extension include, extc++.h.gch/O2.gch
 ${pch3_output}: ${pch3_source} ${pch2_output}