sim: Use host not target byte order for merging and splitting values

When using writes to memory through a struct to merge and extract
multi-word value, it is the endianness of the host, not the target
that affects which order the component words need to be written into
the structure.

Of the 5 functions adjusted here 4 of them are unused.  The 5th,
JOINSIDF will soon be used by the or1k target.

For or1k, simulated on x86-64, this change fixes this function so that
the correct bytes are now returned.

sim/common/ChangeLog:

	* cgen-ops.h (SUBWORDXFSI): Compare HOST_BYTE_ORDER not
	CURRENT_TARGET_BYTE_ORDER.
	(SUBWORDTFSI): Likewise.
	(JOINSIDF): Likewise.
	(JOINSIXF): Likewise.
	(JOINSITF): Likewise.

Author: T-J-Teru

sim/common/ChangeLog

@@ -1,3 +1,12 @@
+2019-04-13  Andrew Burgess  <[email protected]>
+
+	* cgen-ops.h (SUBWORDXFSI): Compare HOST_BYTE_ORDER not
+	CURRENT_TARGET_BYTE_ORDER.
+	(SUBWORDTFSI): Likewise.
+	(JOINSIDF): Likewise.
+	(JOINSIXF): Likewise.
+	(JOINSITF): Likewise.
+
 2019-03-28  Andrew Burgess  <[email protected]>
 
 	* sim-base.h: Add 'sim-assert.h' include.

sim/common/cgen-ops.h

@@ -404,7 +404,7 @@ SUBWORDXFSI (XF in, int word)
   /* Note: typedef struct { SI parts[3]; } XF; */
   union { XF in; SI out[3]; } x;
   x.in = in;
-  if (CURRENT_TARGET_BYTE_ORDER == BFD_ENDIAN_BIG)
+  if (HOST_BYTE_ORDER == BFD_ENDIAN_BIG)
     return x.out[word];
   else
     return x.out[2 - word];
@@ -416,7 +416,7 @@ SUBWORDTFSI (TF in, int word)
   /* Note: typedef struct { SI parts[4]; } TF; */
   union { TF in; SI out[4]; } x;
   x.in = in;
-  if (CURRENT_TARGET_BYTE_ORDER == BFD_ENDIAN_BIG)
+  if (HOST_BYTE_ORDER == BFD_ENDIAN_BIG)
     return x.out[word];
   else
     return x.out[3 - word];
@@ -432,7 +432,7 @@ SEMOPS_INLINE DF
 JOINSIDF (SI x0, SI x1)
 {
   union { SI in[2]; DF out; } x;
-  if (CURRENT_TARGET_BYTE_ORDER == BFD_ENDIAN_BIG)
+  if (HOST_BYTE_ORDER == BFD_ENDIAN_BIG)
     x.in[0] = x0, x.in[1] = x1;
   else
     x.in[1] = x0, x.in[0] = x1;
@@ -443,7 +443,7 @@ SEMOPS_INLINE XF
 JOINSIXF (SI x0, SI x1, SI x2)
 {
   union { SI in[3]; XF out; } x;
-  if (CURRENT_TARGET_BYTE_ORDER == BFD_ENDIAN_BIG)
+  if (HOST_BYTE_ORDER == BFD_ENDIAN_BIG)
     x.in[0] = x0, x.in[1] = x1, x.in[2] = x2;
   else
     x.in[2] = x0, x.in[1] = x1, x.in[0] = x2;
@@ -454,7 +454,7 @@ SEMOPS_INLINE TF
 JOINSITF (SI x0, SI x1, SI x2, SI x3)
 {
   union { SI in[4]; TF out; } x;
-  if (CURRENT_TARGET_BYTE_ORDER == BFD_ENDIAN_BIG)
+  if (HOST_BYTE_ORDER == BFD_ENDIAN_BIG)
     x.in[0] = x0, x.in[1] = x1, x.in[2] = x2, x.in[3] = x3;
   else
     x.in[3] = x0, x.in[2] = x1, x.in[1] = x2, x.in[0] = x3;