increase coverage of building with LDC by using it for the x64-debug build

.azure-pipelines/windows-msbuild.bat

@@ -74,7 +74,8 @@ cp %DMD_DIR%\..\phobos\phobos%MODEL%.lib .
 
 cd "%DMD_DIR%\..\phobos"
 REM Check: build phobos unittests
-if "%D_COMPILER%" == "ldc" cp %LDC_DIR%\lib32\libcurl.dll .
+if "%D_COMPILER%_%MODEL%" == "ldc_64" cp %LDC_DIR%\lib64\libcurl.dll .
+if "%D_COMPILER%_%MODEL%" == "ldc_32mscoff" cp %LDC_DIR%\lib32\libcurl.dll .
 if "%D_COMPILER%_%MODEL%" == "dmd_64" cp %DMD_DIR%\dmd2\windows\bin64\libcurl.dll .
 if "%D_COMPILER%_%MODEL%" == "dmd_32mscoff" cp %DMD_DIR%\dmd2\windows\bin\libcurl.dll .
 "%DM_MAKE%" -f win64.mak unittest MODEL=%MODEL% "DMD=%DMD%" "VCDIR=%VCINSTALLDIR%." "CC=%MSVC_CC%" "MAKE=%DM_MAKE%"

azure-pipelines.yml

@@ -46,7 +46,7 @@ jobs:
           ARCH: x86
           D_COMPILER: ldc
           VISUALD_VER: v0.49.0
-          LDC_VERSION: 1.14.0
+          LDC_VERSION: 1.19.0
     steps:
       - template: .azure-pipelines/windows-visual-studio.yml
 
@@ -56,15 +56,15 @@ jobs:
       vmImage: 'vs2017-win2016'
     variables:
       VSINSTALLDIR: C:\Program Files (x86)\Microsoft Visual Studio\2017\Enterprise\
-      HOST_DMD_VERSION: 2.086.1
     strategy:
       matrix:
-        x64-debug-dmd:
+        x64-debug-ldc:
           OS: Win_64
           MODEL: 64
           ARCH: x64
           CONFIGURATION: Debug
-          D_COMPILER: dmd
+          D_COMPILER: ldc
           VISUALD_VER: v0.49.0
+          LDC_VERSION: 1.19.0
     steps:
       - template: .azure-pipelines/windows-visual-studio.yml