Auto merge of #53951 - tromey:restore-lldb-build, r=alexcrichton

Restore lldb build

commit 6c10142 ("Update LLVM submodule") disabled the lldb build.
This patch updates the lldb and clang submodules to once again build
against the LLVM that is included in the Rust tree, and reverts the
.travis.yml changes from that patch.

.gitmodules

@@ -59,8 +59,8 @@
 [submodule "src/tools/lldb"]
 	path = src/tools/lldb
 	url = https://github.com/rust-lang-nursery/lldb/
-	branch = rust-release-70
+	branch = rust-release-80-v1
 [submodule "src/tools/clang"]
 	path = src/tools/clang
 	url = https://github.com/rust-lang-nursery/clang/
-	branch = release_70
+	branch = rust-release-80-v1

.travis.yml

@@ -30,7 +30,7 @@ matrix:
 
     - env: >
         RUST_CHECK_TARGET=dist
-        RUST_CONFIGURE_ARGS="--enable-extended --enable-profiler"
+        RUST_CONFIGURE_ARGS="--enable-extended --enable-profiler --enable-lldb"
         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"
+        RUST_CONFIGURE_ARGS="--build=i686-apple-darwin --enable-full-tools --enable-profiler --enable-lldb"
         SRC=.
         DEPLOY=1
         RUSTC_RETRY_LINKER_ON_SEGFAULT=1
@@ -101,7 +101,7 @@ 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"
+        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"
         SRC=.
         DEPLOY=1
         RUSTC_RETRY_LINKER_ON_SEGFAULT=1