ci: Explicitly select Ubuntu 16.04 (xenial)

kulp · emilio · commit 5a638c0a1150 · 2020-08-03T17:57:55.000+02:00
Xenial was being used anyway, but it is wise to be explicit. This lets
us download a newer precompiled LLVM, too.
diff --git a/.travis.yml b/.travis.yml
@@ -1,5 +1,7 @@
 language: rust
 
+dist: xenial
+
 os:
   - linux
 
diff --git a/ci/before_install.sh b/ci/before_install.sh
@@ -9,7 +9,7 @@ set -x
 set -o pipefail
 
 function llvm_linux_target_triple() {
-    echo "x86_64-linux-gnu-ubuntu-14.04"
+    echo "x86_64-linux-gnu-ubuntu-16.04"
 }
 
 function llvm_macos_target_triple() {

-Original file line number
+Diff line change
@@ @@ -1,5 +1,7 @@ @@
 language: rust
 +dist: xenial
++
 os:
   - linux
Original file line number	Diff line number	Diff line change
`@@ -9,7 +9,7 @@ set -x`
`9`	`9`	`set -o pipefail`
`10`	`10`
`11`	`11`	`function llvm_linux_target_triple() {`
`12`		`- echo "x86_64-linux-gnu-ubuntu-14.04"`
	`12`	`+ echo "x86_64-linux-gnu-ubuntu-16.04"`
`13`	`13`	`}`
`14`	`14`
`15`	`15`	`function llvm_macos_target_triple() {`