internal/gogrep: make simple call patterns match faster

[quasilyte]

When func call pattern contains no $* inside arguments list,
we can compile it to a more efficient program than a
generic one we're currently using.

For instance, in f($x, $y) pattern the desired number
of arguments is known, it's 2, so we can encode that
into pattern directly and check for the args slice length
instead of doing a variadic matching until we reach opEnd.

The performance gains for gogrep are significant (only relevant benchmarks):

name                           old time/op    new time/op    delta
Match/failCall-8                  653ns ±21%     425ns ± 0%  -34.88%  (p=0.008 n=5+5)
Match/simpleCall-8                674ns ±21%     359ns ± 0%  -46.74%  (p=0.008 n=5+5)
Match/anyCall-8                   827ns ±10%     794ns ± 2%     ~     (p=0.690 n=5+5)
Match/variadicCall-8              491ns ± 4%     289ns ± 0%  -41.13%  (p=0.016 n=5+4)
Match/capture1-8                  220ns ± 3%     212ns ± 1%   -3.62%  (p=0.008 n=5+5)
Match/capture2-8                  328ns ± 2%     312ns ± 0%   -4.97%  (p=0.008 n=5+5)
Match/capture8-8                 1.52µs ± 2%    1.14µs ± 1%  -25.01%  (p=0.008 n=5+5)
Match/capture2same-8              372ns ± 3%     350ns ± 1%   -6.01%  (p=0.008 n=5+5)
Match/capture8same-8             1.70µs ±10%    1.22µs ± 1%  -28.20%  (p=0.008 n=5+5)
Match/captureBacktrackLeft-8     2.23µs ±10%    2.01µs ± 0%   -9.79%  (p=0.008 n=5+5)
Match/captureBacktrackRight-8    1.18µs ± 0%    1.14µs ± 0%   -3.27%  (p=0.008 n=5+5)

name                           old alloc/op   new alloc/op   delta
Match/failCall-8                  48.0B ± 0%     24.0B ± 0%  -50.00%  (p=0.008 n=5+5)
Match/simpleCall-8                72.0B ± 0%     24.0B ± 0%  -66.67%  (p=0.008 n=5+5)
Match/anyCall-8                    136B ± 0%      136B ± 0%     ~     (all equal)
Match/variadicCall-8              72.0B ± 0%     24.0B ± 0%  -66.67%  (p=0.008 n=5+5)
Match/capture1-8                  24.0B ± 0%     24.0B ± 0%     ~     (all equal)
Match/capture2-8                  24.0B ± 0%     24.0B ± 0%     ~     (all equal)
Match/capture8-8                  72.0B ± 0%     24.0B ± 0%  -66.67%  (p=0.008 n=5+5)
Match/capture2same-8              24.0B ± 0%     24.0B ± 0%     ~     (all equal)
Match/capture8same-8              72.0B ± 0%     24.0B ± 0%  -66.67%  (p=0.008 n=5+5)
Match/captureBacktrackLeft-8       280B ± 0%      280B ± 0%     ~     (all equal)
Match/captureBacktrackRight-8      160B ± 0%      160B ± 0%     ~     (all equal)

[cristaloleg]

🚀

[cristaloleg]

looks like inverted version is slightly simpler

[quasilyte]

Fixed.