Re-enable lldb

Commit 7215963 disabled lldb due to the LLVM update.  This patch
updates lldb to build against the Rust LLVM, and re-enables it.

.gitmodules

@@ -56,9 +56,9 @@
 [submodule "src/tools/lldb"]
 	path = src/tools/lldb
 	url = https://github.com/rust-lang-nursery/lldb.git
-	branch = rust-release-80-v1
+	branch = rust-release-80-v2
 [submodule "src/tools/clang"]
 	path = src/tools/clang
 	url = https://github.com/rust-lang-nursery/clang.git
-	branch = rust-release-80-v1
+	branch = rust-release-80-v2
 

.travis.yml

@@ -30,7 +30,7 @@ matrix:
 
     - env: >
         RUST_CHECK_TARGET=dist
-        RUST_CONFIGURE_ARGS="--enable-extended --enable-profiler --set rust.jemalloc"
+        RUST_CONFIGURE_ARGS="--enable-extended --enable-profiler --enable-lldb --set rust.jemalloc"
         SRC=.
         DEPLOY_ALT=1
         RUSTC_RETRY_LINKER_ON_SEGFAULT=1
@@ -87,7 +87,7 @@ matrix:
     # OSX 10.7 and `xcode7` is the latest Xcode able to compile LLVM for 10.7.
     - env: >
         RUST_CHECK_TARGET=dist
-        RUST_CONFIGURE_ARGS="--build=i686-apple-darwin --enable-full-tools --enable-profiler --set rust.jemalloc"
+        RUST_CONFIGURE_ARGS="--build=i686-apple-darwin --enable-full-tools --enable-profiler --enable-lldb --set rust.jemalloc"
         SRC=.
         DEPLOY=1
         RUSTC_RETRY_LINKER_ON_SEGFAULT=1
@@ -102,7 +102,7 @@ matrix:
 
     - env: >
         RUST_CHECK_TARGET=dist
-        RUST_CONFIGURE_ARGS="--target=aarch64-apple-ios,armv7-apple-ios,armv7s-apple-ios,i386-apple-ios,x86_64-apple-ios --enable-full-tools --enable-sanitizers --enable-profiler --set rust.jemalloc"
+        RUST_CONFIGURE_ARGS="--target=aarch64-apple-ios,armv7-apple-ios,armv7s-apple-ios,i386-apple-ios,x86_64-apple-ios --enable-full-tools --enable-sanitizers --enable-profiler --enable-lldb --set rust.jemalloc"
         SRC=.
         DEPLOY=1
         RUSTC_RETRY_LINKER_ON_SEGFAULT=1