Replicate Travis build configurations

The Travis configuration has a set of different build combinations that
the Azure CI config didn't yet have. So replicate that. Only do those
builds on the MoarVM repo. Doing this plethora of build combinations for
changes in downstream projects has little use.

azure-pipelines.yml

@@ -31,8 +31,6 @@ variables:
   MOAR_CHECKOUT_TYPE: "rev-$(Build.SourceVersion)-selfrepo"
   TRIGGERING_REPO: MoarVM
 
-
-
 stages:
 - stage: Test
   condition: ne( variables['BUILD_PRECOMP_RELEASE'], 'yes' )
@@ -94,12 +92,64 @@ stages:
           NQP_OPTIONS: '--backends=moar --relocatable'
           MOAR_OPTIONS: '--relocatable'
 
+         MVM_njit_gcc:
+          ONLY_ON: 'MoarVM'
+          IMAGE_NAME: 'ubuntu-18.04'
+          NQP_OPTIONS: '--backends=moar'
+          MOAR_OPTIONS: '--no-jit --cc=gcc'
+         MVM_gcc:
+          ONLY_ON: 'MoarVM'
+          IMAGE_NAME: 'ubuntu-18.04'
+          NQP_OPTIONS: '--backends=moar'
+          MOAR_OPTIONS: '--cc=gcc'
+         MVM_njit_clang:
+          ONLY_ON: 'MoarVM'
+          IMAGE_NAME: 'ubuntu-18.04'
+          NQP_OPTIONS: '--backends=moar'
+          MOAR_OPTIONS: '--no-jit --cc=clang'
+         MVM_clang:
+          ONLY_ON: 'MoarVM'
+          IMAGE_NAME: 'ubuntu-18.04'
+          NQP_OPTIONS: '--backends=moar'
+          MOAR_OPTIONS: '--cc=clang'
+         MVM_njit_libffi_gcc:
+          ONLY_ON: 'MoarVM'
+          IMAGE_NAME: 'ubuntu-18.04'
+          NQP_OPTIONS: '--backends=moar'
+          MOAR_OPTIONS: '--has-libffi --no-jit --cc=gcc'
+         MVM_libffi_gcc:
+          ONLY_ON: 'MoarVM'
+          IMAGE_NAME: 'ubuntu-18.04'
+          NQP_OPTIONS: '--backends=moar'
+          MOAR_OPTIONS: '--has-libffi --cc=gcc'
+         MVM_njit_libffi_clang:
+          ONLY_ON: 'MoarVM'
+          IMAGE_NAME: 'ubuntu-18.04'
+          NQP_OPTIONS: '--backends=moar'
+          MOAR_OPTIONS: '--has-libffi --no-jit --cc=clang'
+         MVM_libffi_clang:
+          ONLY_ON: 'MoarVM'
+          IMAGE_NAME: 'ubuntu-18.04'
+          NQP_OPTIONS: '--backends=moar'
+          MOAR_OPTIONS: '--has-libffi --cc=clang'
+         MVM_coverage:
+          ONLY_ON: 'MoarVM'
+          IMAGE_NAME: 'ubuntu-18.04'
+          NQP_OPTIONS: '--backends=moar'
+          MOAR_OPTIONS: '--compiler=clang --coverage --optimize=0 --debug=3 --cc=clang'
+          COVERAGE: 1
+          USE_CLANG_LATEST: 1
+
       pool:
         vmImage: $(IMAGE_NAME)
       workspace:
         clean: all
       timeoutInMinutes: 180
-      condition: not( and( eq( variables['TRIGGERING_REPO'], 'MoarVM'), eq( variables['BACKEND'], 'JVM') ) )
+      condition: >
+        and(
+          not( and( eq( variables['TRIGGERING_REPO'], 'MoarVM'), eq( variables['BACKEND'], 'JVM') ) ),
+          or( eq( variables['ONLY_ON'], variables['TRIGGERING_REPO'] ), eq( variables['ONLY_ON'], '' ) )
+        )
       steps:
 
         - pwsh: |
@@ -254,6 +304,14 @@ stages:
           condition: and( eq( variables['RELOCATABLE'], 'yes' ), ne( variables['BACKEND'], 'JVM') )
           displayName: Publish build artifact
 
+        - script: |
+            git clone --depth 1 'https://github.com/samcv/MoarVM-cover.git' &&
+            cp -v MoarVM-cover/html-cover.sh . &&
+            cp -v MoarVM-cover/nqp-profile ../nqp/ &&
+            cp -v MoarVM-cover/merge-profraw.sh ../nqp/ &&
+            ./html-cover.sh 2
+          condition: eq( variables['COVERAGE'], 'yes' )
+
 - stage: Build_Precomp_Release
   condition: eq( variables['BUILD_PRECOMP_RELEASE'], 'yes' )
   jobs: