pgsql: Add test case for trailing junk after numeric literals

Add test case for trailing junk after numeric literals

PostgreSQL currently accepts numeric literals with trailing
non-digits, such as 123abc where the abc is treated as the next token.
This may be a bit surprising. This commit adds test cases for this;
subsequent commits intend to change this behavior.

Reviewed-by: John Naylor <john(dot)naylor(at)enterprisedb(dot)com>
Discussion: https://www.postgresql.org/message-id/flat/b239564c-cad0-b23e-c57e-166d883cb97d(at)enterprisedb(dot)com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/13d129333ee2cc936350cd257af4d0367a6099ac

Modified Files
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src/test/regress/expected/numerology.out | 62 ++++++++++++++++++++++++++++++++
src/test/regress/sql/numerology.sql | 16 +++++++++
2 files changed, 78 insertions(+)