[smuxi/stable] configure.ac: fix "make install" on Mono 5.0

[Mirco M. M. Bauer <mmmbauer src gnome org>]

commit fff7fada1cc4dc2472f47f3de6e77afa32eacb04
Author: Mirco Bauer <meebey meebey net>
Date:   Fri May 19 16:39:45 2017 +0800

    configure.ac: fix "make install" on Mono 5.0
    
    Mono's xbuild >= 5.0 no longer defaults to mcs as compiler but csc which will
    generate debug symbol files named .pdb instead of .mdb. Since we are
    installing the debug symbol files, we override the compiler to mcs to ensure
    the files will be avilable for the install during "make install"
    
        /usr/bin/install: cannot stat ‘../../lib/../bin/debug/ServiceStack.Text.dll.mdb’: No such file or 
directory
        /usr/bin/install: cannot stat ‘../../lib/../bin/debug/ServiceStack.Interfaces.dll.mdb’: No such file 
or directory
        /usr/bin/install: cannot stat ‘../../lib/../bin/debug/ServiceStack.Common.dll.mdb’: No such file or 
directory
        /usr/bin/install: cannot stat ‘../../lib/../bin/debug/Newtonsoft.Json.dll.mdb’: No such file or 
directory
        /usr/bin/install: cannot stat ‘../../lib/../bin/debug/Twitterizer2.dll.mdb’: No such file or directory
        /usr/bin/install: cannot stat ‘../../lib/../bin/debug/Twitterizer2.Streaming.dll.mdb’: No such file 
or directory
        /usr/bin/install: cannot stat ‘../../lib/../bin/debug/agsxmpp.dll.mdb’: No such file or directory
        /usr/bin/install: cannot stat ‘../../lib/../bin/debug/Db4objects.Db4o.dll.mdb’: No such file or 
directory
        /usr/bin/install: cannot stat ‘../../lib/../bin/debug/Meebey.SmartIrc4net.dll.mdb’: No such file or 
directory
        /usr/bin/install: cannot stat ‘../../lib/../bin/debug/StarkSoftProxy.dll.mdb’: No such file or 
directory
        /usr/bin/install: cannot stat ‘../../lib/../bin/debug/Microsoft.AspNet.SignalR.Client.dll.mdb’: No 
such file or directory
        /usr/bin/install: cannot stat ‘../../lib/../bin/debug/JabbR.Client.dll.mdb’: No such file or directory
        make[4]: *** [install-pkgappDATA] Error 1
        make[3]: *** [install-am] Error 2
        make[2]: *** [install-recursive] Error 1
        make[1]: *** [install-recursive] Error 1
        make: *** [distcheck] Error 1

 configure.ac |   11 +++++++++++
 1 files changed, 11 insertions(+), 0 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index ad5c077..14b52d0 100644
--- a/configure.ac
+++ b/configure.ac
@@ -232,6 +232,17 @@ fi
 if test "$CLI_RUNTIME" = "4.5"; then
        XBUILD_FLAGS="/toolsversion:4.0 /p:TargetFrameworkVersion=v4.5 /property:DefineConstants=MONO_4_5"
 fi
+# Mono's xbuild >= 5.0 no longer defaults to mcs as compiler but csc which will
+# generate debug symbol files named .pdb instead of .mdb. Since we are
+# installing the debug symbol files, we override the compiler to mcs to ensure
+# the files will be avilable for the install during "make install"
+AC_MSG_CHECKING([for Mono >= 5.0])
+if $PKG_CONFIG 'mono >= 5.0'; then
+       AC_MSG_RESULT(yes)
+       XBUILD_FLAGS+=" /p:CscToolExe=mcs.exe"
+else
+       AC_MSG_RESULT(no)
+fi
 AC_SUBST(XBUILD_FLAGS)
 
 # Required Libraries