[llvm] [llvm-strings] Use small buffer instead of reading whole file (PR #163073)

[James Henderson via llvm-commits]

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@@ -1,70 +1,107 @@
 ## Show that strings interacting with the read-chunk boundary are reported
 ## correctly. The input files are crafted assuming the native read chunk size
 ## (sys::fs::DefaultReadChunkSize) of 16384 bytes.
+##
+## The inputs, and the expected output lines that are too long to write as
+## CHECK lines, are generated by the Python script at the end of this file,
+## which is run as "%python %s". Each argument describes one part of the
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jh7370 wrote:

It's probably not necessary to say how the python script is run, since it's obvious from the test. I'd hope by switching to named arguments with argparse (see my other comment) that we'd be able to drop most of this description too, as the help text for the options would be enough to describe what's mentioned here.

https://github.com/llvm/llvm-project/pull/163073