[gcmole] Update bootstrap script for static linkage.

This changes gcmole's bootstrapping script so that it always creates
binaries that link libstdc++ statically (both plugin and Clang) and do
not link against unneeded libraries (only Clang). For deployment of
gcmole on our infrastructure, it is much easier to have fewer external
dependencies.

R=machenbach@chromium.org
BUG=v8:8813

Change-Id: If6f2f3cc3b1f661f7dafbb406eaaf2e639981640
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1526002Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#60262}

tools/gcmole/Makefile

@@ -39,7 +39,8 @@ libgcmole.so: gcmole.cc
 	-D__STDC_LIMIT_MACROS -O3 -fomit-frame-pointer -fno-exceptions        \
 	-fno-rtti -fPIC -Woverloaded-virtual -Wcast-qual -fno-strict-aliasing \
 	-pedantic -Wno-long-long -Wall -W -Wno-unused-parameter               \
-	-Wwrite-strings -std=c++0x -shared -o libgcmole.so gcmole.cc
+	-Wwrite-strings -static-libstdc++ -std=c++0x -shared -o libgcmole.so  \
+	gcmole.cc
 
 clean:
 	$(RM) libgcmole.so

tools/gcmole/bootstrap.sh

@@ -27,10 +27,11 @@
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-# This script will build libgcmole.so. Building a recent clang needs a
-# recent GCC, so if you explicitly want to use e.g. GCC 4.8, use:
-#
-#    CC=gcc-4.8 CPP=cpp-4.8 CXX=g++-4.8 CXXFLAGS=-static-libstdc++ CXXCPP=cpp-4.8 ./bootstrap.sh
+# This script will build libgcmole.so as well as a corresponding recent
+# version of Clang and LLVM. The Clang will be built with the locally
+# installed compiler and statically link against the local libstdc++ so
+# that the resulting binary is easier transferable between different
+# environments.
 
 CLANG_RELEASE=8.0
 
@@ -102,7 +103,8 @@ if [ ! -e "${BUILD_DIR}" ]; then
   mkdir "${BUILD_DIR}"
 fi
 cd "${BUILD_DIR}"
-cmake -DCMAKE_BUILD_TYPE=Release -DLLVM_ENABLE_PROJECTS=clang "${LLVM_DIR}"
+cmake -DCMAKE_CXX_FLAGS="-static-libstdc++" -DLLVM_ENABLE_TERMINFO=OFF \
+    -DCMAKE_BUILD_TYPE=Release -DLLVM_ENABLE_PROJECTS=clang "${LLVM_DIR}"
 MACOSX_DEPLOYMENT_TARGET=10.5 make -j"${NUM_JOBS}"
 
 # Strip the clang binary.