[RISCV] Remove implication of F extension for XTHeadFMemIdx from RISCVFeatures.td.

There is no implies rule in RISCVISAInfo.cpp so this makes them
consistent.

Soon RISCVFeatures.td will be used to generate RISCVISAInfo.cpp so
it won't be possible to mismatch.

Author: topperc

llvm/lib/Target/RISCV/RISCVFeatures.td

@@ -1016,8 +1016,7 @@ def HasVendorXTHeadCmo : Predicate<"Subtarget->hasVendorXTHeadCmo()">,
 
 def FeatureVendorXTHeadFMemIdx
     : RISCVExtension<"xtheadfmemidx", 1, 0,
-                     "'xtheadfmemidx' (T-Head FP Indexed Memory Operations)",
-                     [FeatureStdExtF]>;
+                     "'xtheadfmemidx' (T-Head FP Indexed Memory Operations)">;
 def HasVendorXTHeadFMemIdx : Predicate<"Subtarget->hasVendorXTHeadFMemIdx()">,
                              AssemblerPredicate<(all_of FeatureVendorXTHeadFMemIdx),
                                  "'xtheadfmemidx' (T-Head FP Indexed Memory Operations)">;

llvm/test/CodeGen/RISCV/attributes.ll

@@ -326,7 +326,7 @@
 ; RV32XSFVFWMACCQQQ: .attribute 5, "rv32i2p1_f2p2_zicsr2p0_zve32f1p0_zve32x1p0_zvfbfmin1p0_zvl32b1p0_xsfvfwmaccqqq1p0"
 ; RV32XTHEADCMO: .attribute 5, "rv32i2p1_xtheadcmo1p0"
 ; RV32XTHEADCONDMOV: .attribute 5, "rv32i2p1_xtheadcondmov1p0"
-; RV32XTHEADFMEMIDX: .attribute 5, "rv32i2p1_f2p2_zicsr2p0_xtheadfmemidx1p0"
+; RV32XTHEADFMEMIDX: .attribute 5, "rv32i2p1_xtheadfmemidx1p0"
 ; RV32XTHEADMAC: .attribute 5, "rv32i2p1_xtheadmac1p0"
 ; RV32XTHEADMEMIDX: .attribute 5, "rv32i2p1_xtheadmemidx1p0"
 ; RV32XTHEADMEMPAIR: .attribute 5, "rv32i2p1_xtheadmempair1p0"
@@ -452,7 +452,7 @@
 ; RV64XTHEADBS: .attribute 5, "rv64i2p1_xtheadbs1p0"
 ; RV64XTHEADCMO: .attribute 5, "rv64i2p1_xtheadcmo1p0"
 ; RV64XTHEADCONDMOV: .attribute 5, "rv64i2p1_xtheadcondmov1p0"
-; RV64XTHEADFMEMIDX: .attribute 5, "rv64i2p1_f2p2_zicsr2p0_xtheadfmemidx1p0"
+; RV64XTHEADFMEMIDX: .attribute 5, "rv64i2p1_xtheadfmemidx1p0"
 ; RV64XTHEADMAC: .attribute 5, "rv64i2p1_xtheadmac1p0"
 ; RV64XTHEADMEMIDX: .attribute 5, "rv64i2p1_xtheadmemidx1p0"
 ; RV64XTHEADMEMPAIR: .attribute 5, "rv64i2p1_xtheadmempair1p0"