Fix LLVM on Windows

.azure/install-llvm.yml

@@ -29,19 +29,27 @@ steps:
     displayName: "Install LLVM (Linux)"
     condition: eq(variables['Agent.OS'], 'Linux')
 
-  - bash: |
-      set -ex
-      if [ -x "`command -v llvm-config`" ]; then
-        echo `command -v cmake` `llvm-config --version` installed
-      else
-        mkdir C:\projects\deps
-        cd C:\projects\deps
-        curl -OL https://github.com/wasmerio/windows-llvm-build/releases/download/v8.0.0/llvm-8.0.0-install.zip
-        7z x llvm-8.0.0-install.zip
-        echo "##vso[task.prependpath]/c/projects/deps/llvm-8.0.0-install/bin"
-        echo "##vso[task.setvariable variable=LLVM_SYS_80_PREFIX]C:\\projects\\deps\\llvm-8.0.0-install"
-      fi
-    displayName: "Install LLVM (Windows)"
+  # - bash: |
+  #     set -ex
+  #     if [ -x "`command -v llvm-config`" ]; then
+  #       echo `command -v cmake` `llvm-config --version` installed
+  #     else
+  #       mkdir C:\projects\deps
+  #       cd C:\projects\deps
+  #       curl -OL https://github.com/wasmerio/windows-llvm-build/releases/download/v8.0.0/llvm-8.0.0-install.zip
+  #       7z x llvm-8.0.0-install.zip
+  #       echo "##vso[task.prependpath]/c/projects/deps/llvm-8.0.0-install/bin"
+  #       echo "##vso[task.setvariable variable=LLVM_SYS_80_PREFIX]C:\\projects\\deps\\llvm-8.0.0-install"
+  #     fi
+  #   displayName: "Install LLVM (Windows)"
+  #   condition: eq(variables['Agent.OS'], 'Windows_NT')
+
+  - powershell: |
+      Invoke-WebRequest https://github.com/wasmerio/windows-llvm-build/releases/download/v8.0.0/llvm-8.0.0-install.zip
+      7z x llvm-8.0.0-install.zip
+      Write-Host "##vso[task.prependpath]$pwd/llvm-8.0.0-install/bin"
+      Write-Host "##vso[task.setvariable variable=LLVM_SYS_80_PREFIX;]$pwd/llvm-8.0.0-install/"
+    displayName: Install LLVM (Windows)
     condition: eq(variables['Agent.OS'], 'Windows_NT')
 
   - bash: |