azure: use bash scripts across all platforms

Right now, we maintain semantically equivalent build scripts in
both Bash and Powershell to support both Windows and non-Windows
hosts. Azure Pipelines supports Bash on Windows, too, via Git for
Windows, and as such it's not really required to maintain the
Powershell scripts at all.

Remove them to reduce our own maintenance burden.

Author: pks-t

azure-pipelines.yml

@@ -78,7 +78,7 @@ jobs:
   displayName: 'Windows (amd64; Visual Studio)'
   pool: Hosted
   steps:
-  - template: azure-pipelines/powershell.yml
+  - template: azure-pipelines/bash.yml
     parameters:
       environmentVariables:
         CMAKE_GENERATOR: Visual Studio 12 2013 Win64
@@ -88,7 +88,7 @@ jobs:
   displayName: 'Windows (x86; Visual Studio)'
   pool: Hosted
   steps:
-  - template: azure-pipelines/powershell.yml
+  - template: azure-pipelines/bash.yml
     parameters:
       environmentVariables:
         CMAKE_GENERATOR: Visual Studio 12 2013
@@ -103,7 +103,7 @@ jobs:
     env:
       TEMP: $(Agent.TempDirectory)
       ARCH: amd64
-  - template: azure-pipelines/powershell.yml
+  - template: azure-pipelines/bash.yml
     parameters:
       environmentVariables:
         BUILD_PATH: $(Agent.TempDirectory)\mingw64\bin;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Program Files (x86)\CMake\bin
@@ -120,7 +120,7 @@ jobs:
     env:
       TEMP: $(Agent.TempDirectory)
       ARCH: x86
-  - template: azure-pipelines/powershell.yml
+  - template: azure-pipelines/bash.yml
     parameters:
       environmentVariables:
         BUILD_PATH: $(Agent.TempDirectory)\mingw32\bin;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Program Files (x86)\CMake\bin

azure-pipelines/build.ps1

@@ -79,7 +79,7 @@ jobs:
   displayName: 'Windows (amd64; Visual Studio)'
   pool: Hosted
   steps:
-  - template: powershell.yml
+  - template: bash.yml
     parameters:
       environmentVariables:
         CMAKE_GENERATOR: Visual Studio 12 2013 Win64
@@ -90,7 +90,7 @@ jobs:
   displayName: 'Windows (x86; Visual Studio)'
   pool: Hosted
   steps:
-  - template: powershell.yml
+  - template: bash.yml
     parameters:
       environmentVariables:
         CMAKE_GENERATOR: Visual Studio 12 2013
@@ -106,7 +106,7 @@ jobs:
     env:
       TEMP: $(Agent.TempDirectory)
       ARCH: amd64
-  - template: powershell.yml
+  - template: bash.yml
     parameters:
       environmentVariables:
         BUILD_PATH: $(Agent.TempDirectory)\mingw64\bin;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Program Files (x86)\CMake\bin
@@ -124,7 +124,7 @@ jobs:
     env:
       TEMP: $(Agent.TempDirectory)
       ARCH: x86
-  - template: powershell.yml
+  - template: bash.yml
     parameters:
       environmentVariables:
         BUILD_PATH: $(Agent.TempDirectory)\mingw32\bin;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Program Files (x86)\CMake\bin