Add clang-tools-extra, lld and lldb to the scripts

The scripts aren't very consistent about which repos they handle (e.g.
clang-tools-extra was handled in llvm-prepare, but not in the other scripts).
This commit tries to improve on that by:
* adding support for clang-tools-extra in llvm-projs, llvm-sync and llvm-branch
* adding support for lld and lldb to llvm-branch.

Change-Id: I82b0aeb95b5116d1d75f0721e0c4d31c4744e04b
diff --git a/helpers/llvm-sync b/helpers/llvm-sync
index bd46404..4ed2203 100755
--- a/helpers/llvm-sync
+++ b/helpers/llvm-sync
@@ -16,7 +16,8 @@
 }
 
 prog=`basename $0`
-syntax="Syntax: $prog [-compiler(r)T] [-(l)ibs] [-Lin(k)er] [-(d)ebugger] [-(t)ests] [-(w)eb pages] [-(a)ll]"
+syntax="Syntax: $prog [-clang-tools-e(x)tra] [-compiler(r)T] [-(l)ibs] [-Lin(k)er] [-(d)ebugger] [-(t)ests] [-(w)eb pages] [-(a)ll]"
+cextra=false
 rt=false
 libs=false
 linker=false
@@ -24,8 +25,11 @@
 tests=false
 web=false
 
-while getopts "rlkdtwa" opt; do
+while getopts "xrlkdtwa" opt; do
   case $opt in
+    x)
+      cextra=true
+      ;;
     r)
       rt=true
       ;;
@@ -45,6 +49,7 @@
       web=true
       ;;
     a)
+      cextra=true
       rt=true
       libs=true
       linker=true
@@ -63,6 +68,10 @@
 repo_sync Clang $LLVM_SRC/../clang
 
 # Optional updates
+if $cextra; then
+  repo_sync ClangToolsExtra $LLVM_SRC/../clang-tools-extra
+fi
+
 if $rt; then
   repo_sync RT $LLVM_SRC/../compiler-rt
 fi