tasks.json: Switch to using ninja for builds.

Much quicker at incremental builds.
Also print when the build has finished.

Change-Id: I3bd74ddb501b4a2584fc2cbd9bd85b250ce117be
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/31834
Reviewed-by: Antonio Maiorano <amaiorano@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>
Tested-by: Ben Clayton <bclayton@google.com>
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>

.vscode/tasks.json

diff --git a/.vscode/tasks.json b/.vscode/tasks.json
index 7a88e94..37da9b3 100644
--- a/.vscode/tasks.json
+++ b/.vscode/tasks.json
@@ -21,19 +21,19 @@
             "osx": {
                 "args": [
                     "-c",
-                    "make -j$(sysctl -n hw.logicalcpu)"
+                    "cmake --build . && echo Done"
                 ]
             },
             "linux": {
                 "args": [
                     "-c",
-                    "make -j$(nproc)"
+                    "cmake --build . && echo Done"
                 ]
             },
             "windows": {
                 "args": [
                     "-c",
-                    "make"
+                    "cmake --build . && echo Done"
                 ]
             },
             "options": {
@@ -66,6 +66,7 @@
             "command": "cmake",
             "args": [
                 "..",
+                "-GNinja",
                 "-DCMAKE_BUILD_TYPE=${input:buildType}",
                 "-DWARNINGS_AS_ERRORS=1",
                 "-DDCHECK_ALWAYS_ON=1"