[polari] build: Add missing check for C compiler

[Florian Müllner <fmuellner src gnome org>]

commit 0f7b73ef94f431200c0c5a24b754b821c2fd8817
Author: Florian Müllner <fmuellner gnome org>
Date:   Thu Sep 17 13:46:23 2015 +0200

    build: Add missing check for C compiler
    
    Meh, how did I miss that all that time? While at it, enable compiler
    warnings for non-releases ...

 configure.ac        |    5 +++++
 src/Makefile-lib.am |    4 ++--
 2 files changed, 7 insertions(+), 2 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 685b24a..11cd363 100644
--- a/configure.ac
+++ b/configure.ac
@@ -17,6 +17,11 @@ IT_PROG_INTLTOOL([0.50.0])
 
 GOBJECT_INTROSPECTION_REQUIRE([0.9.6])
 
+AX_CHECK_ENABLE_DEBUG([yes])
+AX_COMPILER_FLAGS()
+
+AC_PROG_CC
+
 # Initialize libtool
 AM_PROG_AR
 LT_PREREQ([2.2])
diff --git a/src/Makefile-lib.am b/src/Makefile-lib.am
index 466b9c2..68ce5d3 100644
--- a/src/Makefile-lib.am
+++ b/src/Makefile-lib.am
@@ -15,8 +15,8 @@ libpolari_sources = \
 libpolari_1_0_la_SOURCES = $(libpolari_headers) $(libpolari_sources)
 
 libpolari_1_0_la_LIBADD = $(POLARI_LIBS)
-libpolari_1_0_la_CFLAGS = $(POLARI_CFLAGS)
-libpolari_1_0_la_LDFLAGS = -avoid-version
+libpolari_1_0_la_CFLAGS = $(POLARI_CFLAGS) $(WARN_CFLAGS)
+libpolari_1_0_la_LDFLAGS = -avoid-version $(WARN_LDFLAGS)
 
 INTROSPECTION_GIRS += Polari-1.0.gir