Do not check for feclearexcept

Unlike feenableexcept and fedisableexcept, which are GNU
extensions, feclearexcept is part of C99.

https://en.cppreference.com/w/c/header/fenv.html

meson.build

@@ -137,7 +137,7 @@ check_headers = [
   ['sys/wait.h'],
   ['sys/stat.h'],
   ['io.h'],
-  ['fenv.h', {'check-funcs': ['feenableexcept', 'fedisableexcept', 'feclearexcept']}],
+  ['fenv.h', {'check-funcs': ['feenableexcept', 'fedisableexcept']}],
   ['xlocale.h'],
   ['sys/ioctl.h'],
   ['intsafe.h'],

test/invalid-matrix.c

@@ -29,6 +29,8 @@
 #include "config.h"
 #include "cairo-test.h"
 
+#include <fenv.h>
+
 #if !defined(INFINITY)
 #define INFINITY HUGE_VAL
 #endif
@@ -361,7 +363,7 @@ if ((status) == CAIRO_STATUS_SUCCESS) {							\
     CHECK_STATUS (status, "cairo_rotate(∞)");
     cairo_destroy (cr2);
 
-#if HAVE_FECLEAREXCEPT
+#if FE_ALL_EXCEPT
     feclearexcept (FE_INVALID);
 #endif