build: Add -lm to the tests linker flags

https://bugzilla.gnome.org/show_bug.cgi?id=657529

tests/interactive/Makefile.am

@@ -123,7 +123,7 @@ test_interactive_CPPFLAGS = \
 	-DCOGL_DISABLE_DEPRECATED \
 	-DCLUTTER_DISABLE_DEPRECATED
 test_interactive_LDFLAGS = -export-dynamic
-test_interactive_LDADD = $(CLUTTER_LIBS) $(common_ldadd)
+test_interactive_LDADD = $(CLUTTER_LIBS) $(common_ldadd) -lm
 
 EXTRA_DIST = wrapper.sh.in
 DISTCLEANFILES = wrapper.sh .gitignore

tests/micro-bench/Makefile.am

@@ -22,7 +22,7 @@ AM_CFLAGS = \
 	-DG_DISABLE_SINGLE_INCLUDES \
 	-DTESTS_DATA_DIR=\""$(top_srcdir)/tests/data/"\"
 
-LDADD = $(common_ldadd) $(CLUTTER_LIBS)
+LDADD = $(common_ldadd) $(CLUTTER_LIBS) -lm
 
 test_text_SOURCES = test-text.c
 test_picking_SOURCES = test-picking.c

tests/performance/Makefile.am

@@ -12,10 +12,12 @@ noinst_PROGRAMS = \
 INCLUDES = \
 	-I$(top_srcdir)/ \
 	-I$(top_srcdir)/clutter \
-	-I$(top_srcdir)/clutter/cogl \
-	-I$(top_builddir)/clutter \
-	-I$(top_builddir)/clutter/cogl
-LDADD = $(top_builddir)/clutter/libclutter-@CLUTTER_SONAME_INFIX@-@CLUTTER_API_VERSION@.la $(CLUTTER_LIBS)
+	-I$(top_builddir)/clutter
+
+common_ldadd = $(top_builddir)/clutter/libclutter-@CLUTTER_SONAME_INFIX@-@CLUTTER_API_VERSION@.la
+
+LDADD = $(common_ldadd) $(CLUTTER_LIBS) -lm
+
 AM_CFLAGS = \
 	$(CLUTTER_CFLAGS) \
 	$(MAINTAINER_CFLAGS) \