Set up CI with Azure Pipelines

First crack at this. I'm sure there are problems. Just builds Linux with clang8 for now [skip ci]

Author: Greg Roth

azure-pipelines.yml

@@ -0,0 +1,41 @@
+# Starter pipeline
+# Start with a minimal pipeline that you can customize to build and deploy your code.
+# Add steps that build, run tests, deploy, and more:
+# https://aka.ms/yaml
+
+variables:
+  configuration: Release
+
+resources:
+- repo: self
+
+stages:
+- stage: Build
+  jobs:
+  job: Linux_clang8
+    pool:
+      vmImage: Ubuntu-18.04
+
+    variables:
+      CC: clang-8
+      CXX: clang++-8
+
+    steps:
+    - bash: sudo apt-get install clang-8 libc++-8-dev libc++abi-8-dev lld-8 ninja-build python3
+      displayName: 'Installing dependencies'
+    - bash: git submodule update --init
+      displayName: 'Updating submodules'
+    - bash: mkdir build && cd build
+    - bash: cmake .. -GNinja $(cat ../utils/cmake-predefined-config-params) -DSPIRV_BUILD_TESTS=ON -DCMAKE_BUILD_TYPE=$(configuration)
+      displayName: 'Cmake configuration'
+    - bash: ninja
+      displayName: 'Building'
+    - bash: |
+        ./bin/dxc -T ps_6_0 ../tools/clang/test/CodeGenSPIRV/passthru-ps.hlsl2spv
+        ./bin/dxc -T ps_6_0 -Fo passthru-ps.dxil ../tools/clang/test/CodeGenSPIRV/passthru-ps.hlsl2spv
+        ./bin/dxc -T ps_6_0 -Fo passthru-ps.spv ../tools/clang/test/CodeGenSPIRV/passthru-ps.hlsl2spv -spirv
+      displayName: 'Smoke tests'
+    - bash: ./bin/clang-spirv-tests --spirv-test-root ../tools/clang/test/CodeGenSPIRV/
+      displayName: 'SPIRV tests'
+    - bash: ./bin/clang-hlsl-tests --HlslDataDir $PWD/../tools/clang/test/HLSL/
+      displayName: 'DXIL tests'