arm: don't treat XScale features as part of the FPU [PR 28031]

Although the XScale and its iwMMX extensions are implemented in the
Arm co-processor space, they are not considered to be part of the FPU
specification.  In particular, they cannot be enabled or disabled via
a .fpu directive.  It's therefore incorrect to strip these properties
when a new .fpu directive is encountered.

Note that the legacy Maverick co-processor is considered to be a FPU
and it is possible to control this via the .fpu directive.

include:

	PR gas/28031
	* opcode/arm.h (FPU_ANY): Exclude XScale-related features.

include/ChangeLog

@@ -1,3 +1,8 @@
+2021-07-01  Richard Earnshaw  <rearnsha@arm.com>
+
+	PR gas/28031
+	* opcode/arm.h (FPU_ANY): Exclude XScale-related features.
+
 2021-06-18  H.J. Lu  <hongjiu.lu@intel.com>
 
 	* elf/common.h (GNU_PROPERTY_UINT32_AND_LO): New.

include/opcode/arm.h

@@ -383,7 +383,7 @@
 #define ARM_ARCH_NONE	ARM_FEATURE_LOW (0, 0)
 #define FPU_NONE	ARM_FEATURE_LOW (0, 0)
 #define ARM_ANY		ARM_FEATURE (-1, -1 & ~ (ARM_EXT2_MVE | ARM_EXT2_MVE_FP), 0)	/* Any basic core.  */
-#define FPU_ANY		ARM_FEATURE_COPROC (-1) /* Any FPU.  */
+#define FPU_ANY		ARM_FEATURE_COPROC (-1 & ~(ARM_CEXT_XSCALE | ARM_CEXT_IWMMXT | ARM_CEXT_IWMMXT2)) /* Any FPU.  */
 #define FPU_ANY_HARD	ARM_FEATURE_COPROC (FPU_FPA | FPU_VFP_HARD | FPU_MAVERICK)
 /* Extensions containing some Thumb-2 instructions.  If any is present, Thumb
    ISA is Thumb-2.  */