[VMR] Add basic WASM CI (#18573)

Author: lewing

eng/pipelines/templates/jobs/vmr-build.yml

@@ -271,7 +271,10 @@ jobs:
         fi
 
         if [[ -n "${{ parameters.crossRootFs }}" ]]; then
-          customEnvVars="$customEnvVars ROOTFS_DIR=${{ parameters.crossRootFs}} CROSSCOMPILE=1"
+          customEnvVars="$customEnvVars ROOTFS_DIR=${{ parameters.crossRootFs}}"
+          if [[ '${{ parameters.targetArchitecture }}' != 'wasm' ]]; then
+            customEnvVars="$customEnvVars CROSSCOMPILE=1"
+          fi
         fi
 
         if [[ ! -z '${{ parameters.targetOS }}' ]]; then

eng/pipelines/templates/stages/vmr-build.yml

@@ -345,6 +345,20 @@ stages:
         targetOS: windows
         targetArchitecture: x64
 
+    - template: ../jobs/vmr-build.yml
+      parameters:
+        buildName: Browser_Shortstack
+        isBuiltFromVmr: ${{ parameters.isBuiltFromVmr }}
+        vmrBranch: ${{ variables.VmrBranch }}
+        architecture: wasm
+        pool:
+          name: ${{ variables.defaultPoolName }}
+          demands: ${{ variables.defaultPoolDemandsLinux }}
+        container: ${{ variables.wasmCrossContainer }}
+        crossRootFs: '/crossrootfs/x64'
+        targetOS: browser
+        targetArchitecture: wasm
+
     - template: ../jobs/vmr-build.yml
       parameters:
         buildName: iOSSimulator_Shortstack
@@ -457,6 +471,20 @@ stages:
             targetOS: tvossimulator
             targetArchitecture: x64
 
+        - template: ../jobs/vmr-build.yml
+          parameters:
+            buildName: Wasi_Shortstack
+            isBuiltFromVmr: ${{ parameters.isBuiltFromVmr }}
+            vmrBranch: ${{ variables.VmrBranch }}
+            architecture: wasm
+            pool:
+              name: ${{ variables.defaultPoolName }}
+              demands: ${{ variables.defaultPoolDemandsLinux }}
+            container: ${{ variables.wasmCrossContainer }}
+            crossRootFs: '/crossrootfs/x64'
+            targetOS: wasi
+            targetArchitecture: wasm
+
         - template: ../jobs/vmr-build.yml
           parameters:
             buildName: OSX

eng/pipelines/templates/variables/vmr-stage.yml

@@ -28,6 +28,8 @@ variables:
   value: mcr.microsoft.com/dotnet-buildtools/prereqs:cbl-mariner-2.0-cross-arm64
 - name: androidCrossContainer
   value: mcr.microsoft.com/dotnet-buildtools/prereqs:cbl-mariner-2.0-cross-android-amd64
+- name: wasmCrossContainer
+  value: mcr.microsoft.com/dotnet-buildtools/prereqs:cbl-mariner-2.0-webassembly-20230917141449-2aaa02c
 
 - ${{ if eq(variables['System.TeamProject'], 'public') }}:
   - name: defaultPoolName