test/codegen: combine trivial PPC64 tests into ppc64x

Use a small python script to consolidate duplicate
ppc64/ppc64le tests into a single ppc64x codegen test.

This makes small assumption that anytime two tests with
for different arch/variant combos exists, those tests
can be combined into a single ppc64x test.

E.x:

  // ppc64le: foo
  // ppc64le/power9: foo
into
  // ppc64x: foo

or

  // ppc64: foo
  // ppc64le: foo
into
  // ppc64x: foo

import glob
import re
files = glob.glob("codegen/*.go")
for file in files:
    with open(file) as f:
        text = [l for l in f]
    i = 0
    while i < len(text):
        first = re.match("\s*// ?ppc64(le)?(/power[89])?:(.*)", text[i])
        if first:
            j = i+1
            while j < len(text):
                second = re.match("\s*// ?ppc64(le)?(/power[89])?:(.*)", text[j])
                if not second:
                    break
                if (not first.group(2) or first.group(2) == second.group(2)) and first.group(3) == second.group(3):
                    text[i] = re.sub(" ?ppc64(le|x)?"," ppc64x",text[i])
                    text=text[:j] + (text[j+1:])
                else:
                    j += 1
        i+=1
    with open(file, 'w') as f:
        f.write("".join(text))

Change-Id: Ic6b009b54eacaadc5a23db9c5a3bf7331b595821
Reviewed-on: https://go-review.googlesource.com/c/go/+/463220


Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: Lynn Boger <laboger@linux.vnet.ibm.com>
Reviewed-by: Bryan Mills <bcmills@google.com>
Run-TryBot: Paul Murphy <murp@ibm.com>
TryBot-Result: Gopher Robot <gobot@golang.org>