dont look for immintrin on GCC pre-4.4. Also dont build with -maes; need to autoconfig other flags

Makefile

@@ -50,7 +50,7 @@ endif
 TODAY = $(shell date "+%Y-%m-%d")
 
 #FIXME ARCHFLAGS
-ARCHFLAGS ?= -maes -mavx2 -mbmi2 #TODO
+ARCHFLAGS ?= -mavx2 -mbmi2 #TODO
 
 ifeq ($(CC),clang)
 WARNFLAGS_C += -Wgcc-compat

src/GENERATED/include/decaf/ed255.hxx

@@ -149,9 +149,7 @@ public:
     inline SecureBuffer sign (
         const Block &message,
         const Block &context = NO_CONTEXT()
-    ) const /* TODO: this exn spec tickles a Clang bug?
-             * throw(LengthException, std::bad_alloc)
-             */ {
+    ) const /* throw(LengthException, std::bad_alloc) */ {
         if (context.size() > 255) {
             throw LengthException();
         }

src/GENERATED/include/decaf/ed448.hxx

@@ -149,9 +149,7 @@ public:
     inline SecureBuffer sign (
         const Block &message,
         const Block &context = NO_CONTEXT()
-    ) const /* TODO: this exn spec tickles a Clang bug?
-             * throw(LengthException, std::bad_alloc)
-             */ {
+    ) const /* throw(LengthException, std::bad_alloc) */ {
         if (context.size() > 255) {
             throw LengthException();
         }

src/include/word.h

@@ -36,7 +36,11 @@ extern int posix_memalign(void **, size_t, size_t);
 #if defined(__ARM_NEON__)
 #include <arm_neon.h>
 #elif defined(__SSE2__)
-#include <immintrin.h>
+    #if !defined(__GNUC__) || __clang__ || __GNUC__ >= 5 || (__GNUC__==4 && __GNUC_MINOR__ >= 4)
+        #include <immintrin.h>
+    #else
+        #include <emmintrin.h>
+    #endif
 #endif
 
 #if (ARCH_WORD_BITS == 64)

src/per_curve/eddsa.tmpl.hxx

@@ -133,9 +133,7 @@ public:
     inline SecureBuffer sign (
         const Block &message,
         const Block &context = NO_CONTEXT()
-    ) const /* TODO: this exn spec tickles a Clang bug?
-             * throw(LengthException, std::bad_alloc)
-             */ {
+    ) const /* throw(LengthException, std::bad_alloc) */ {
         if (context.size() > 255) {
             throw LengthException();
         }