[7/15][Clang][RISCV][NFC] Correct the default value for Policy to TAMU

[eopXD]

Summary

The default value is set to Omit, but in fact the value is then
assigned in updateNamesAndPolicy, which is set to TUMU when masked and
TAMU when unmasked. This commit demonstrates so and further remove
another dependency of Omit.

This is the 7th commit of a patch-set that aims to change the default policy
for RVV intrinsics from TAMU to TAMA.

Please refer to the cover letter in the 1st commit (D141573) for an
overview.

[eopXD]

Bump CI

[eopXD]

Update code: default is TAMU.

[eopXD]

Rebase upon latest main.

[eopXD]

Bump CI.

[kito-cheng]

LGTM

[craig.topper]

LGTM

clang/include/clang/Support/RISCVVIntrinsicUtils.h

 
 struct Policy {
   bool IsUnspecified = false;
   enum PolicyType {
     Undisturbed,
     Agnostic,
     Omit, // No policy required.
   };
-  PolicyType TailPolicy = Omit;
-  PolicyType MaskPolicy = Omit;
+  PolicyType TailPolicy = Agnostic;
+  PolicyType MaskPolicy = Undisturbed;
   Policy() : IsUnspecified(true) {}
   Policy(PolicyType _TailPolicy, PolicyType _MaskPolicy)
       : TailPolicy(_TailPolicy), MaskPolicy(_MaskPolicy) {}
 
   bool isTAMAPolicy() const {
     return TailPolicy == Agnostic && MaskPolicy == Agnostic;
   }