Ok, here are some benchmark results with your patch:

### call_method ###
Min: 0.313816 -> 0.305150: 1.03x faster
Avg: 0.316292 -> 0.305678: 1.03x faster
Significant (t=21.07)
Stddev: 0.00188 -> 0.00050: 3.7398x smaller
Timeline: http://tinyurl.com/couzwbe

### call_method_unknown ###
Min: 0.323125 -> 0.312034: 1.04x faster
Avg: 0.325697 -> 0.313115: 1.04x faster
Significant (t=17.62)
Stddev: 0.00258 -> 0.00099: 2.6059x smaller
Timeline: http://tinyurl.com/clwacj3

### call_simple ###
Min: 0.215008 -> 0.220773: 1.03x slower
Avg: 0.215666 -> 0.221657: 1.03x slower
Significant (t=-23.28)
Stddev: 0.00062 -> 0.00078: 1.2721x larger
Timeline: http://tinyurl.com/cv6gxft

### fastpickle ###
Min: 0.554353 -> 0.569768: 1.03x slower
Avg: 0.558192 -> 0.574705: 1.03x slower
Significant (t=-6.90)
Stddev: 0.00363 -> 0.00393: 1.0829x larger
Timeline: http://tinyurl.com/c8s2dqk

### float ###
Min: 0.292259 -> 0.279563: 1.05x faster
Avg: 0.296011 -> 0.286154: 1.03x faster
Significant (t=2.99)
Stddev: 0.00417 -> 0.00609: 1.4585x larger
Timeline: http://tinyurl.com/c34ofe5

### iterative_count ###
Min: 0.115091 -> 0.118527: 1.03x slower
Avg: 0.116174 -> 0.119266: 1.03x slower
Significant (t=-6.82)
Stddev: 0.00068 -> 0.00075: 1.1148x larger
Timeline: http://tinyurl.com/bsmuuso

### json_dump_v2 ###
Min: 2.591838 -> 2.652666: 1.02x slower
Avg: 2.599335 -> 2.687225: 1.03x slower
Significant (t=-8.09)
Stddev: 0.00715 -> 0.02322: 3.2450x larger
Timeline: http://tinyurl.com/clxutkt

### json_load ###
Min: 0.378329 -> 0.370132: 1.02x faster
Avg: 0.379840 -> 0.371222: 1.02x faster
Significant (t=13.68)
Stddev: 0.00112 -> 0.00085: 1.3237x smaller
Timeline: http://tinyurl.com/c7ycte2

### nbody ###
Min: 0.259945 -> 0.251294: 1.03x faster
Avg: 0.261186 -> 0.251843: 1.04x faster
Significant (t=14.95)
Stddev: 0.00125 -> 0.00062: 2.0274x smaller
Timeline: http://tinyurl.com/cg8z6yg

### nqueens ###
Min: 0.295304 -> 0.275767: 1.07x faster
Avg: 0.298382 -> 0.278839: 1.07x faster
Significant (t=10.19)
Stddev: 0.00244 -> 0.00353: 1.4429x larger
Timeline: http://tinyurl.com/bo2dn4x

### pathlib ###
Min: 0.100494 -> 0.102371: 1.02x slower
Avg: 0.101787 -> 0.104876: 1.03x slower
Significant (t=-8.15)
Stddev: 0.00103 -> 0.00159: 1.5432x larger
Timeline: http://tinyurl.com/cb9w79t

### richards ###
Min: 0.166939 -> 0.172828: 1.04x slower
Avg: 0.167945 -> 0.174199: 1.04x slower
Significant (t=-9.65)
Stddev: 0.00092 -> 0.00112: 1.2241x larger
Timeline: http://tinyurl.com/cdros5x

### silent_logging ###
Min: 0.070485 -> 0.066857: 1.05x faster
Avg: 0.070538 -> 0.067041: 1.05x faster
Significant (t=44.64)
Stddev: 0.00003 -> 0.00017: 5.4036x larger
Timeline: http://tinyurl.com/buz5h9j

### 2to3 ###
0.490925 -> 0.478927: 1.03x faster

### chameleon ###
Min: 0.050694 -> 0.049364: 1.03x faster
Avg: 0.051030 -> 0.049759: 1.03x faster
Significant (t=8.45)
Stddev: 0.00041 -> 0.00041: 1.0036x larger
Timeline: b'http://tinyurl.com/d5czdjt'

### mako ###
Min: 0.183295 -> 0.177191: 1.03x faster
Avg: 0.184944 -> 0.179300: 1.03x faster
Significant (t=15.54)
Stddev: 0.00119 -> 0.00137: 1.1555x larger
Timeline: b'http://tinyurl.com/dx6xrvx'


In the end, it's mostly a wash.