Fix ambiguous FillVRegs template specializations

The two specializations with <char FirstArgType, char...ArgType> and
<char ...ArgType> are ambiguous after
https://github.com/llvm/llvm-project/pull/100692.  For e.g.,
MaterializeVRegs<'L', 'L'> can match both specializations:
  ArgType = <'L', 'L'>, and
  FirstArgType = 'L', ArgType = <'L'>

The first (now-deleted) specialization can match calls with any number
of template parameters, including zero.  The second specialization
matches calls with one or more parameters.  To avoid the ambiguity,
delete the first specialization and explicitly avoid calls with zero
template parameters.

Bug: http://b/363682086
Test: mmma art with ToT clang; and presubmit
Change-Id: I4a3737b4098180faa1f889c2bba475846acc8a51

0 files changed, 0 insertions, 0 deletions