build: Use PTHREAD_LIBS and PTHREAD_CFLAGS
diff --git a/configure.ac b/configure.ac
index dc2720d..b8f5514 100644
--- a/configure.ac
+++ b/configure.ac
@@ -871,8 +871,8 @@
     GL_PC_REQ_PRIV="x11 xext"
     X11_INCLUDES="$X11_INCLUDES $XLIBGL_CFLAGS"
     GL_LIB_DEPS="$XLIBGL_LIBS"
-    GL_LIB_DEPS="$GL_LIB_DEPS $SELINUX_LIBS -lm -lpthread $DLOPEN_LIBS"
-    GL_PC_LIB_PRIV="$GL_PC_LIB_PRIV $SELINUX_LIBS -lm -lpthread"
+    GL_LIB_DEPS="$GL_LIB_DEPS $SELINUX_LIBS -lm $PTHREAD_LIBS $DLOPEN_LIBS"
+    GL_PC_LIB_PRIV="$GL_PC_LIB_PRIV $SELINUX_LIBS -lm $PTHREAD_LIBS"
     ;;
 xyesno)
     # DRI-based GLX
@@ -899,9 +899,9 @@
     X11_INCLUDES="$X11_INCLUDES $DRIGL_CFLAGS"
     GL_LIB_DEPS="$DRIGL_LIBS"
 
-    # need DRM libs, -lpthread, etc.
-    GL_LIB_DEPS="$GL_LIB_DEPS $LIBDRM_LIBS -lm -lpthread $DLOPEN_LIBS"
-    GL_PC_LIB_PRIV="-lm -lpthread $DLOPEN_LIBS"
+    # need DRM libs, $PTHREAD_LIBS, etc.
+    GL_LIB_DEPS="$GL_LIB_DEPS $LIBDRM_LIBS -lm $PTHREAD_LIBS $DLOPEN_LIBS"
+    GL_PC_LIB_PRIV="-lm $PTHREAD_LIBS $DLOPEN_LIBS"
     ;;
 esac
 
@@ -909,10 +909,10 @@
 # builds.
 AM_CONDITIONAL(HAVE_XF86VIDMODE, test "x$HAVE_XF86VIDMODE" = xyes)
 
-GLESv1_CM_LIB_DEPS="$LIBDRM_LIBS -lm -lpthread $DLOPEN_LIBS"
-GLESv1_CM_PC_LIB_PRIV="-lm -lpthread $DLOPEN_LIBS"
-GLESv2_LIB_DEPS="$LIBDRM_LIBS -lm -lpthread $DLOPEN_LIBS"
-GLESv2_PC_LIB_PRIV="-lm -lpthread $DLOPEN_LIBS"
+GLESv1_CM_LIB_DEPS="$LIBDRM_LIBS -lm $PTHREAD_LIBS $DLOPEN_LIBS"
+GLESv1_CM_PC_LIB_PRIV="-lm $PTHREAD_LIBS $DLOPEN_LIBS"
+GLESv2_LIB_DEPS="$LIBDRM_LIBS -lm $PTHREAD_LIBS $DLOPEN_LIBS"
+GLESv2_PC_LIB_PRIV="-lm $PTHREAD_LIBS $DLOPEN_LIBS"
 
 AC_SUBST([X11_INCLUDES])
 AC_SUBST([GL_LIB_DEPS])
@@ -1099,8 +1099,8 @@
     fi
 
     # put all the necessary libs together
-    DRI_LIB_DEPS="$DRI_LIB_DEPS $SELINUX_LIBS $LIBDRM_LIBS $EXPAT_LIB -lm -lpthread $DLOPEN_LIBS"
-    GALLIUM_DRI_LIB_DEPS="$GALLIUM_DRI_LIB_DEPS $SELINUX_LIBS $LIBDRM_LIBS $EXPAT_LIB -lm -lpthread $DLOPEN_LIBS"
+    DRI_LIB_DEPS="$DRI_LIB_DEPS $SELINUX_LIBS $LIBDRM_LIBS $EXPAT_LIB -lm $PTHREAD_LIBS $DLOPEN_LIBS"
+    GALLIUM_DRI_LIB_DEPS="$GALLIUM_DRI_LIB_DEPS $SELINUX_LIBS $LIBDRM_LIBS $EXPAT_LIB -lm $PTHREAD_LIBS $DLOPEN_LIBS"
 fi
 AC_SUBST([DRI_DIRS])
 AC_SUBST([EXPAT_INCLUDES])
@@ -1196,12 +1196,12 @@
 if test "x$enable_osmesa" = xyes; then
     # only link libraries with osmesa if shared
     if test "$enable_static" = no; then
-        OSMESA_LIB_DEPS="-lm -lpthread $SELINUX_LIBS $DLOPEN_LIBS"
+        OSMESA_LIB_DEPS="-lm $PTHREAD_LIBS $SELINUX_LIBS $DLOPEN_LIBS"
     else
         OSMESA_LIB_DEPS=""
     fi
     OSMESA_MESA_DEPS=""
-    OSMESA_PC_LIB_PRIV="-lm -lpthread $SELINUX_LIBS $DLOPEN_LIBS"
+    OSMESA_PC_LIB_PRIV="-lm $PTHREAD_LIBS $SELINUX_LIBS $DLOPEN_LIBS"
 fi
 
 AC_SUBST([OSMESA_LIB_DEPS])
@@ -1247,7 +1247,7 @@
 
 if test "x$enable_egl" = xyes; then
     SRC_DIRS="$SRC_DIRS egl"
-    EGL_LIB_DEPS="$DLOPEN_LIBS $SELINUX_LIBS -lpthread"
+    EGL_LIB_DEPS="$DLOPEN_LIBS $SELINUX_LIBS $PTHREAD_LIBS"
 
     AC_CHECK_FUNC(mincore, [DEFINES="$DEFINES -DHAVE_MINCORE"])
 
@@ -1370,11 +1370,11 @@
     fi
 
     EGL_CLIENT_APIS="$EGL_CLIENT_APIS "'$(VG_LIB)'
-    VG_LIB_DEPS="$VG_LIB_DEPS $SELINUX_LIBS -lpthread"
+    VG_LIB_DEPS="$VG_LIB_DEPS $SELINUX_LIBS $PTHREAD_LIBS"
     CORE_DIRS="$CORE_DIRS mapi/vgapi"
     GALLIUM_STATE_TRACKERS_DIRS="vega $GALLIUM_STATE_TRACKERS_DIRS"
     HAVE_ST_VEGA=yes
-    VG_PC_LIB_PRIV="-lm -lpthread $DLOPEN_LIBS"
+    VG_PC_LIB_PRIV="-lm $PTHREAD_LIBS $DLOPEN_LIBS"
     AC_SUBST([VG_PC_LIB_PRIV])
 fi