Add a linker test re: section alignment

testsuite/tests/rts/linker/Makefile

@@ -6,3 +6,8 @@ unsigned_reloc_macho_x64:
 	as -o unsigned_reloc_macho_x64.o unsigned_reloc_macho_x64.s
 	'$(TEST_HC)' $(TEST_HC_OPTS_NO_RTSOPTS) -v0 --make -no-rtsopts-suggestions -no-hs-main -o runner runner.c
 	./runner unsigned_reloc_macho_x64.o getAnswer
+
+aligned_mem_access:
+	cc -c -o aligned_mem_access.o aligned_mem_access.c
+	'$(TEST_HC)' $(TEST_HC_OPTS_NO_RTSOPTS) -v0 --make -no-rtsopts-suggestions -no-hs-main -o runner runner.c
+	./runner aligned_mem_access.o foo

testsuite/tests/rts/linker/aligned_mem_access.c

+#include <stdio.h>
+#include <immintrin.h>
+
+__m128 mvec   = {1.0, 2.0, 3.0, 42.0};
+float  fvec[] = {.0, .0, .0, .0};
+
+/* Uses movaps instruction to move data between XMMn <-> mem. Fails
+ * with segfault when data section is not properly aligned (16 byte).
+ */
+long foo(void)
+{
+        _mm_store_ps(fvec, mvec);
+        return (long) fvec[3];
+}

testsuite/tests/rts/linker/aligned_mem_access.stdout

+Linking: path = aligned_mem_access.o, symname = _foo
+42
\ No newline at end of file

testsuite/tests/rts/linker/all.T

@@ -7,3 +7,10 @@ test('unsigned_reloc_macho_x64',
          unless(arch('x86_64'), skip)
      ],
      run_command, ['$MAKE -s --no-print-directory unsigned_reloc_macho_x64'])
+
+test('aligned_mem_access',
+     [
+         extra_files(['runner.c', 'aligned_mem_access.c']),
+         unless(opsys('darwin') and arch('x86_64'), expect_broken(13624))
+     ],
+     run_command, ['$MAKE -s --no-print-directory aligned_mem_access'])