gnu: fplll: Correct include files.

* gnu/packages/patches/fplll-std-fenv.patch: New patch.
* gnu/local.mk (dist_patch_DATA): Register patch.
* gnu/packages/algebra.scm (fplll): Use patch and move all inputs to
propagated-inputs.

gnu/local.mk

@@ -968,6 +968,7 @@ dist_patch_DATA =						\
   %D%/packages/patches/foomatic-filters-CVE-2015-8560.patch	\
   %D%/packages/patches/fontconfig-hurd-path-max.patch		\
   %D%/packages/patches/fpc-reproducibility.patch		\
+  %D%/packages/patches/fplll-std-fenv.patch     		\
   %D%/packages/patches/freedink-engine-fix-sdl-hints.patch	\
   %D%/packages/patches/freeimage-unbundle.patch		\
   %D%/packages/patches/fuse-overlapping-headers.patch				\

gnu/packages/algebra.scm

@@ -160,14 +160,15 @@ line applications.")
               (file-name (git-file-name name version))
               (sha256
                (base32
-                "06nyfidagp8pc2kfcw88ldgb2b1xm0a8z31n0sln7j72ihlmd8zj"))))
+                "06nyfidagp8pc2kfcw88ldgb2b1xm0a8z31n0sln7j72ihlmd8zj"))
+              (patches (search-patches "fplll-std-fenv.patch"))))
     (build-system gnu-build-system)
     (native-inputs
      `(("autoconf" ,autoconf)
        ("automake" ,automake)
        ("libtool" ,libtool)
        ("pkg-config" ,pkg-config)))
-    (inputs
+    (propagated-inputs ; header files pulled in by fplll/defs.h
      `(("gmp" ,gmp)
        ("mpfr" ,mpfr)))
     (home-page "https://github.com/fplll/fplll")

gnu/packages/patches/fplll-std-fenv.patch

@@ -0,0 +1,18 @@
+See https://github.com/fplll/fplll/issues/444
+
+--- fplll-5.3.3-checkout.old/fplll/enum/enumerate_base.h	2020-09-23 13:55:27.833769823 +0200
++++ fplll-5.3.3-checkout/fplll/enum/enumerate_base.h	2020-09-23 13:56:14.313771769 +0200
+@@ -127,10 +127,10 @@
+   int rounding_backup;
+   void save_rounding()
+   {
+-    rounding_backup = std::fegetround();
+-    std::fesetround(FE_TONEAREST);
++    rounding_backup = fegetround();
++    fesetround(FE_TONEAREST);
+   }
+-  void restore_rounding() { std::fesetround(rounding_backup); }
++  void restore_rounding() { fesetround(rounding_backup); }
+ 
+   inline bool next_pos_up()
+   {