Add configure options for MAX_WIDTH/HEIGHT.

This adds two --with configure options for setting defines for
MAX_WIDTH and MAX_HEIGHT.  It's conceivably just as easy to define
these in CFLAGS manually, but this way users don't need to know
about internal Mesa details.

Patch updated by BrianP to set DEFINES, not CFLAGS.

(cherry picked from master, commit 7085dce750)

configure.ac

@@ -1145,6 +1145,21 @@ AC_ARG_WITH([xorg-driver-dir],
     [XORG_DRIVER_INSTALL_DIR="${libdir}/xorg/modules/drivers"])
 AC_SUBST([XORG_DRIVER_INSTALL_DIR])
 
+AC_ARG_WITH([max-width],
+    [AS_HELP_STRING([--with-max-width=N],
+                    [Maximum framebuffer width (4096)])],
+    [DEFINES="${DEFINES} -DMAX_WIDTH=${withval}";
+     AS_IF([test "${withval}" -gt "4096"],
+           [AC_MSG_WARN([Large framebuffer: see s_tritemp.h comments.])])]
+)
+AC_ARG_WITH([max-height],
+    [AS_HELP_STRING([--with-max-height=N],
+                    [Maximum framebuffer height (4096)])],
+    [DEFINES="${DEFINES} -DMAX_HEIGHT=${withval}";
+     AS_IF([test "${withval}" -gt "4096"],
+           [AC_MSG_WARN([Large framebuffer: see s_tritemp.h comments.])])]
+)
+
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 dnl Gallium Intel configuration
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