fix: minor fixes for clock stuff

[AayushSabharwal]

Checklist

• Appropriate tests were added
• Any code changes were done in a way that does not break public API
• All documentation related to code changes were updated
• The new code follows the
  contributor guidelines, in particular the SciML Style Guide and
  COLPRAC.
• Any new documentation only uses public API

Additional context

Add any other context about the problem here.

[github-actions]

Benchmark Results (Julia vlts)

Time benchmarks

	master	b29aa5d...	master / b29aa5d...
ODEProblem	0.0871 ± 0.0051 s	0.0888 ± 0.0064 s	0.981 ± 0.091
init	0.0573 ± 0.0014 ms	0.0571 ± 0.0014 ms	1 ± 0.035
large_parameter_init/ODEProblem	1.04 ± 0.0065 s	1.02 ± 0.006 s	1.02 ± 0.0088
large_parameter_init/init	0.108 ± 0.0018 ms	0.108 ± 0.0021 ms	0.994 ± 0.025
mtkcompile	0.0317 ± 0.00087 s	0.0323 ± 0.0012 s	0.98 ± 0.045
sparse_analytical_jacobian/ODEProblem	0.216 ± 0.0069 s	0.215 ± 0.0083 s	1.01 ± 0.05
sparse_analytical_jacobian/f_iip	0.08 ± 0.01 μs	0.07 ± 0 μs	1.14 ± 0.14
sparse_analytical_jacobian/f_oop	0.381 ± 0.0087 ms	0.38 ± 0.0092 ms	1 ± 0.033
time_to_load	4.91 ± 0.015 s	4.95 ± 0.019 s	0.991 ± 0.005

Memory benchmarks

	master	b29aa5d...	master / b29aa5d...
ODEProblem	0.659 M allocs: 22.1 MB	0.659 M allocs: 22.1 MB	1
init	0.892 k allocs: 0.046 MB	0.892 k allocs: 0.046 MB	1
large_parameter_init/ODEProblem	4.23 M allocs: 0.164 GB	4.21 M allocs: 0.163 GB	1.01
large_parameter_init/init	1.74 k allocs: 0.0856 MB	1.74 k allocs: 0.0856 MB	1
mtkcompile	0.229 M allocs: 8.46 MB	0.229 M allocs: 8.46 MB	1
sparse_analytical_jacobian/ODEProblem	0.82 M allocs: 29.3 MB	0.819 M allocs: 29.3 MB	1
sparse_analytical_jacobian/f_iip	0 allocs: 0 B	0 allocs: 0 B
sparse_analytical_jacobian/f_oop	0.634 k allocs: 19.6 kB	0.634 k allocs: 19.6 kB	1
time_to_load	0.153 k allocs: 14.5 kB	0.153 k allocs: 14.5 kB	1

[github-actions]

Benchmark Results (Julia v1)

Time benchmarks

	master	b29aa5d...	master / b29aa5d...
ODEProblem	0.101 ± 0.0051 s	0.109 ± 0.0092 s	0.926 ± 0.091
init	0.0456 ± 0.012 ms	0.0467 ± 0.013 ms	0.975 ± 0.36
large_parameter_init/ODEProblem	1.22 ± 0.065 s	1.24 ± 0.016 s	0.987 ± 0.054
large_parameter_init/init	0.085 ± 0.018 ms	0.0837 ± 0.02 ms	1.02 ± 0.32
mtkcompile	0.0384 ± 0.0028 s	0.0389 ± 0.0018 s	0.987 ± 0.085
sparse_analytical_jacobian/ODEProblem	0.26 ± 0.0092 s	0.271 ± 0.0092 s	0.96 ± 0.047
sparse_analytical_jacobian/f_iip	0.08 ± 0.001 μs	0.08 ± 0.001 μs	1 ± 0.018
sparse_analytical_jacobian/f_oop	0.121 ± 0.014 ms	0.123 ± 0.013 ms	0.988 ± 0.16
time_to_load	5.26 ± 0.043 s	5.26 ± 0.024 s	0.999 ± 0.0093

Memory benchmarks

	master	b29aa5d...	master / b29aa5d...
ODEProblem	0.672 M allocs: 22.1 MB	0.673 M allocs: 22.2 MB	0.998
init	0.797 k allocs: 30.5 kB	0.797 k allocs: 30.5 kB	1
large_parameter_init/ODEProblem	4.49 M allocs: 0.166 GB	4.47 M allocs: 0.164 GB	1.01
large_parameter_init/init	1.64 k allocs: 0.0594 MB	1.64 k allocs: 0.0594 MB	1
mtkcompile	0.234 M allocs: 8 MB	0.234 M allocs: 8 MB	0.999
sparse_analytical_jacobian/ODEProblem	0.894 M allocs: 30.2 MB	0.896 M allocs: 30.3 MB	0.998
sparse_analytical_jacobian/f_iip	0 allocs: 0 B	0 allocs: 0 B
sparse_analytical_jacobian/f_oop	0.848 k allocs: 27 kB	0.848 k allocs: 27 kB	1
time_to_load	0.149 k allocs: 11.1 kB	0.149 k allocs: 11.1 kB	1

[ChrisRackauckas]

how does this come up?

[AayushSabharwal]

In fixpoint_sub when building MTKParameters. Hold(x) is stored as a parameter, so an initial value for x is an initial value for Hold(x).