bug 1250971 - pass cgthreads with number of cores for Windows PGO builds. r=gps

MozReview-Commit-ID: Hf5QoDHXPUz

--HG--
extra : commitid : 42qB3HeFqda
extra : rebase_source : 21048ea52c2e0ef60eaac79b886048016c6204c0
extra : amend_source : 11f4ec10f94338e7af283164dc1300e7cd96233b
extra : histedit_source : b0e629b9eee1bcfffb312a3a43a137c7c957e0e0

old-configure.in

@@ -2192,7 +2192,9 @@ ia64*-hpux*)
         fi
         dnl For profile-guided optimization
         PROFILE_GEN_CFLAGS="-GL"
-        PROFILE_GEN_LDFLAGS="-LTCG:PGINSTRUMENT"
+        num_cores=$($PYTHON -c 'import multiprocessing; print(min(8,multiprocessing.cpu_count()))')
+        cgthreads="-CGTHREADS:${num_cores}"
+        PROFILE_GEN_LDFLAGS="-LTCG:PGINSTRUMENT $cgthreads"
         dnl XXX: PGO builds can fail with warnings treated as errors,
         dnl specifically "no profile data available" appears to be
         dnl treated as an error sometimes. This might be a consequence
@@ -2203,7 +2205,7 @@ ia64*-hpux*)
         PROFILE_USE_CFLAGS="-GL -wd4624 -wd4952"
         dnl XXX: should be -LTCG:PGOPTIMIZE, but that fails on libxul.
         dnl Probably also a compiler bug, but what can you do?
-        PROFILE_USE_LDFLAGS="-LTCG:PGUPDATE"
+        PROFILE_USE_LDFLAGS="-LTCG:PGUPDATE $cgthreads"
         LDFLAGS="$LDFLAGS -DYNAMICBASE"
         RCFLAGS="-nologo"
         if test "$_CC_MAJOR_VERSION" = "18" -a "$_CC_BUILD_VERSION" = "31101"; then