Merge 'Refactor numeric literal' from meteorgan

Closes #1461

testing/all.test

@@ -30,3 +30,4 @@ source $testdir/update.test
 source $testdir/drop_table.test
 source $testdir/default_value.test
 source $testdir/boolean.test
+source $testdir/literal.test

testing/literal.test

@@ -0,0 +1,84 @@
+#!/usr/bin/env tclsh
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+
+do_execsql_test numberic-literal-1 {
+  SELECT 45;
+} {45}
+
+do_execsql_test numberic-literal-2 {
+  SELECT 0x7FFFFFFFFFFFFFFF;
+} {9223372036854775807}
+
+do_execsql_test numberic-literal-3 {
+  SELECT -0x7FFFFFFFFFFFFFFF;
+} {-9223372036854775807}
+
+do_execsql_test numberic-literal-4 {
+  SELECT +0x7FFFFFFFFFFFFFFF;
+} {9223372036854775807}
+
+do_execsql_test numberic-literal-5 {
+  SELECT 9_223_372_036_854_775_807;
+} {9223372036854775807}
+
+do_execsql_test numberic-literal-6 {
+  SELECT -9_223_372_036_854_775_808;
+} {-9223372036854775808}
+
+do_execsql_test numberic-literal-7 {
+  SELECT 1_000;
+} {1000}
+
+do_execsql_test numberic-literal-8 {
+  SELECT 1.1_1;
+} {1.11}
+
+do_execsql_test numberic-literal-9 {
+  SELECT 1e12;
+} {1000000000000.0}
+
+do_execsql_test numberic-literal-10 {
+  SELECT 1.0;
+} {1.0}
+
+do_execsql_test numberic-literal-11 {
+  SELECT 1e1000;
+} {Inf}
+
+do_execsql_test numberic-literal-12 {
+  SELECT -1e1000;
+} {-Inf}
+
+do_execsql_test numberic-literal-13 {
+  SELECT 1e1_000;
+} {Inf}
+
+do_execsql_test numberic-literal-14 {
+  SELECT 12_3_456.7_8_9;
+} {123456.789}
+
+do_execsql_test numberic-literal-exceed-max-i64 {
+  SELECT 9_223_372_036_854_775_808;
+} {9.22337203685478e+18}
+
+do_execsql_test numberic-literal-exceed-min-i64 {
+  SELECT -9_223_372_036_854_775_809;
+} {-9.22337203685478e+18}
+
+do_execsql_test_any_error invalid-numberic-literal-1 {
+  SELECT 0xFF__FF;
+}
+
+do_execsql_test_any_error invalid-numberic-literal-2 {
+  SELECT 12a3;
+}
+
+do_execsql_test_any_error invalid-numberic-literal-3 {
+  SELECT e12;
+}
+
+do_execsql_test_any_error invalid-numberic-literal-4 {
+  SELECT 1e;
+}