[COMMITTED] C-SKY: Fix expanding of float LE comparing with zero for fpuv3.

  The original code will cause the warning:
/usr/lib/gcc-snapshot/bin/g++  -fno-PIE -c   -g -O2   -DIN_GCC  -DCROSS_DIRECTORY_STRUCTURE   -fno-exceptions -fno-rtti -fasynchronous-unwind-tables -W -Wall -Wno-narrowing -Wwrite-strings -Wcast-qual -Wmissing-format-attribute -Woverloaded-virtual -pedantic -Wno-long-long -Wno-variadic-macros -Wno-overlength-strings -Werror -fno-common  -DHAVE_CONFIG_H -I. -I. -I../../gcc/gcc -I../../gcc/gcc/. -I../../gcc/gcc/../include -I../../gcc/gcc/../libcpp/include -I../../gcc/gcc/../libcody  -I../../gcc/gcc/../libdecnumber -I../../gcc/gcc/../libdecnumber/dpd -I../libdecnumber -I../../gcc/gcc/../libbacktrace   -o csky.o -MT csky.o -MMD -MP -MF ./.deps/csky.TPo ../../gcc/gcc/config/csky/csky.cc
In file included from ../../gcc/gcc/config/csky/csky.h:183,
                from ./tm.h:20,
                from ../../gcc/gcc/backend.h:28,
                from ../../gcc/gcc/config/csky/csky.cc:27:
../../gcc/gcc/config/csky/csky.cc: In function 'bool csky_emit_compare_float(rtx_code, rtx, rtx)':
../../gcc/gcc/config/csky/csky_isa.h:29:37: error: enum constant in boolean context [-Werror=int-in-bool-context]
  29 | #define CSKY_ISA_FEATURE_DEFINE(x)  isa_bit_ ## x
      |                                     ^~~~~~~~
../../gcc/gcc/config/csky/csky_isa.h:30:37: note: in expansion of macro 'CSKY_ISA_FEATURE_DEFINE'
  30 | #define CSKY_ISA_FEATURE_GET(x)     CSKY_ISA_FEATURE_DEFINE (x)
      |                                     ^~~~~~~~~~~~~~~~~~~~~~~
../../gcc/gcc/config/csky/csky.cc:6346:43: note: in expansion of macro 'CSKY_ISA_FEATURE_GET'
6346 |                                        || CSKY_ISA_FEATURE_GET(fpv2_df)
      |                                           ^~~~~~~~~~~~~~~~~~~~
../../gcc/gcc/config/csky/csky_isa.h:29:37: error: enum constant in boolean context [-Werror=int-in-bool-context]
  29 | #define CSKY_ISA_FEATURE_DEFINE(x)  isa_bit_ ## x
      |                                     ^~~~~~~~
../../gcc/gcc/config/csky/csky_isa.h:30:37: note: in expansion of macro 'CSKY_ISA_FEATURE_DEFINE'
  30 | #define CSKY_ISA_FEATURE_GET(x)     CSKY_ISA_FEATURE_DEFINE (x)
      |                                     ^~~~~~~~~~~~~~~~~~~~~~~
../../gcc/gcc/config/csky/csky.cc:6346:43: note: in expansion of macro 'CSKY_ISA_FEATURE_GET'
6346 |                                        || CSKY_ISA_FEATURE_GET(fpv2_df)
      |                                           ^~~~~~~~~~~~~~~~~~~~
../../gcc/gcc/config/csky/csky_isa.h:29:37: error: enum constant in boolean context [-Werror=int-in-bool-context]
  29 | #define CSKY_ISA_FEATURE_DEFINE(x)  isa_bit_ ## x
      |                                     ^~~~~~~~
../../gcc/gcc/config/csky/csky_isa.h:30:37: note: in expansion of macro 'CSKY_ISA_FEATURE_DEFINE'
  30 | #define CSKY_ISA_FEATURE_GET(x)     CSKY_ISA_FEATURE_DEFINE (x)
      |                                     ^~~~~~~~~~~~~~~~~~~~~~~
../../gcc/gcc/config/csky/csky.cc:6347:43: note: in expansion of macro 'CSKY_ISA_FEATURE_GET'
6347 |                                        || CSKY_ISA_FEATURE_GET(fpv2_divd)))
      |                                           ^~~~~~~~~~~~~~~~~~~~

The 'CSKY_ISA_FEATURE_DEFINE (x)' is an enum contant, it will cause the condition always being true.
In addition to warning, it will let FPUV3 to generate a move instruction, which is unnecessary.
In a simple test case, the move instruction can be combined, so it was not found in the testsuite.
But in some complex scenarios, this may generate some redundant instructions.
The correct way is to use 'CSKY_ISA_FEATURE' instead of 'CSKY_ISA_FEATURE_DEFINE'.

gcc/
	* config/csky/csky.cc (csky_emit_compare_float): Fix the expanding of
	float LE comparing with zero for fpuv3.
	* config/csky/csky.h (TARGET_SUPPORT_FPV2): New, true if any fpuv2
	features are enabled.
---
 gcc/config/csky/csky.cc | 4 +---
 gcc/config/csky/csky.h  | 4 ++++
 2 files changed, 5 insertions(+), 3 deletions(-)