Removed some unwanted code

Signed-off-by: joydeep049 <[email protected]>

model/riscv_sys_regs.sail

@@ -262,67 +262,6 @@ function set_mstatus_UXL(m : Mstatus, a : arch_xlen) -> Mstatus = {
   }
 }
 
-val extension : (string) -> bool
-
-/* helper to check support for various extensions. */
-/* we currently don't model 'E', so always assume 'I'. */
-function extension(ext) = {
-  match ext {
-    "A" => misa.A() == 0b1,
-    "C" => misa.C() == 0b1,
-
-    /* F and D extensions have to enabled both via misa.{FD} as well as mstatus.FS */
-    "D" => (misa.D() == 0b1) & (mstatus.FS() != 0b00),
-    "F" => (misa.F() == 0b1) & (mstatus.FS() != 0b00),
-
-    "M" => misa.M() == 0b1,
-    "N" => misa.N() == 0b1,
-    "U" => misa.U() == 0b1,
-    "S" => misa.S() == 0b1,
-
-    /* V extension has to enable both via misa.V as well as mstatus.VS */
-    "V" => (misa.V() == 0b1) & (mstatus.VS() != 0b00),
-
-    /* BitManip extension support. */
-    "Zba" => true,
-    "Zbb" => true,
-    "Zbc" => true,
-    "Zbs" => true,
-
-    /* Scalar Cryptography extensions support. */
-    "Zbkb" => true,
-    "Zbkc" => true,
-    "Zbkx" => true,
-
-    /* Zfa (additional FP) extension */
-    "Zfa" => true,
-
-    /* Zfh (half-precision) extension depends on misa.F and mstatus.FS */
-    "Zfh" => (misa.F() == 0b1) & (mstatus.FS() != 0b00),
-
-    /* Zhinx, Zfinx and Zdinx extensions (TODO: gate FCSR access on [mhs]stateen0 bit 1 when implemented) */
-    "Zdinx" => sys_enable_zfinx() & sizeof(flen) >= 64,
-    "Zfinx" => sys_enable_zfinx(),
-    "Zhinx" => sys_enable_zfinx(),
-
-    /* Zicond extension support */
-    "Zicond" => true,
-
-    /* Cryptography extension support. Note these will need updating once */
-    /* Sail can be dynamically configured with different extension support */
-    /* and have dynamic changes of XLEN via S/UXL */
-    "Zkr" => true,
-    "Zksh" => true,
-    "Zksed" => true,
-    "Zknd" => true,
-    "Zkne" => true,
-    "Zknh" => true,
-
-    "Zmmul" => true,
-    _ => false
-  }
-}
-
 function legalize_mstatus(o : Mstatus, v : xlenbits) -> Mstatus = {
   /*
    * Populate all defined fields using the bits of v, stripping anything