[PATCH 15/16][fold-const.c] Fix bigendian HFmode in native_interpret_real

[Alan Lawrence]

As per https://gcc.gnu.org/ml/gcc-patches/2015-04/msg01346.html. Fixes FAIL of 
advsimd-intrinsics vcreate.c on aarch64_be-none-elf from previous patch.
commit e2e7ca148960a82fc88128820f17e7cbd14173cb
Author: Alan Lawrence <alan.lawre...@arm.com>
Date:   Thu Apr 9 10:54:40 2015 +0100
    Fix native_interpret_real for HFmode floats on Bigendian with UNITS_PER_WORD>=4
    
    (with missing space)

diff --git a/gcc/fold-const.c b/gcc/fold-const.c
index e61d946..15a10f0 100644
--- a/gcc/fold-const.c
+++ b/gcc/fold-const.c
@@ -7622,7 +7622,7 @@ native_interpret_real (tree type, const unsigned char *ptr, int len)
 	    offset += byte % UNITS_PER_WORD;
 	}
       else
-	offset = BYTES_BIG_ENDIAN ? 3 - byte : byte;
+	offset = BYTES_BIG_ENDIAN ? MIN (3, total_bytes - 1) - byte : byte;
       value = ptr[offset + ((bitpos / BITS_PER_UNIT) & ~3)];
 
       tmp[bitpos / 32] |= (unsigned long)value << (bitpos & 31);