pgsql: Use appendStringInfoString() where appropriate in elog.c.

Use appendStringInfoString() where appropriate in elog.c.

The nominally equivalent call appendStringInfo(buf, "%s", str) can be
significantly slower when str is large. In particular, the former usage in
EVALUATE_MESSAGE led to O(N^2) behavior when collecting a large number of
context lines, as I found out while testing recursive functions. The other
changes are just neatnik-ism and seem unlikely to save anything meaningful,
but a cycle shaved is a cycle earned.

Branch
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master

Details
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http://git.postgresql.org/gitweb?p=postgresql.git;a=commitdiff;h=09211659d9d8fd62f9de09703c90ed4f072c4a47

Modified Files
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src/backend/utils/error/elog.c | 51 ++++++++++++++++++++++-----------------
1 files changed, 29 insertions(+), 22 deletions(-)