Help the parser run faster by avoiding the "explain ::= ." production.

FossilOrigin-Name: d7ec7b5970df9e542401f8299e098a5039d1875e2e3383dad06a0ec998589b6e

manifest

@@ -1,5 +1,5 @@
-C Prohibit\sbound\sparameters\sin\sthe\sarguments\sto\stable-valued\sfunctions\swithin\na\strigger.\s\sProblem\sdiscovered\sby\sOSSFuzz.
-D 2018-04-11T16:04:01.145
+C Help\sthe\sparser\srun\sfaster\sby\savoiding\sthe\s"explain\s::=\s."\sproduction.
+D 2018-04-11T17:10:54.632
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F Makefile.in 7016fc56c6b9bfe5daac4f34be8be38d8c0b5fab79ccbfb764d3b23bf1c6fff3
@@ -480,7 +480,7 @@ F src/os_win.c eb03c6d52f893bcd7fdd4c6006674c13c1b5e49543fec98d605201af2997171c
 F src/os_win.h 7b073010f1451abe501be30d12f6bc599824944a
 F src/pager.c 1bb6a57fa0465296a4d6109a1a64610a0e7adde1f3acf3ef539a9d972908ce8f
 F src/pager.h c571b064df842ec8f2e90855dead9acf4cbe0d1b2c05afe0ef0d0145f7fd0388
-F src/parse.y 22ca6e5bb34bbf94e4f91bb1cae6fefad7c03c2e0f29fe9b14b4192e8421f234
+F src/parse.y e3c4116efb7d693df412bd42a96c88c6463704d31a29342c2fa671f6e91ecb26
 F src/pcache.c 135ef0bc6fb2e3b7178d49ab5c9176254c8a691832c1bceb1156b2fbdd0869bd
 F src/pcache.h 072f94d29281cffd99e46c1539849f248c4b56ae7684c1f36626797fee375170
 F src/pcache1.c 716975564c15eb6679e97f734cec1bfd6c16ac3d4010f05f1f8e509fc7d19880
@@ -1717,7 +1717,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P f32cdb41ca213cfcfe0bb5bfe56930d43e55525fa5640274b00f1ccce7f69634
-R 7c8229c67bab778254c73d883b02f8cd
+P b7178209152452e82f5908513385018524472640d67547927d6b4c0aa0c15a46
+R 12b886afc6216ee0a5a2b22cc4bff5a5
 U drh
-Z d47d1a7f91fccc9da7ff7a7b98373d3d
+Z 93376c77c8408e036fdadd56852c955d

manifest.uuid

@@ -1 +1 @@
-b7178209152452e82f5908513385018524472640d67547927d6b4c0aa0c15a46
+d7ec7b5970df9e542401f8299e098a5039d1875e2e3383dad06a0ec998589b6e

src/parse.y

@@ -114,9 +114,9 @@ input ::= cmdlist.
 cmdlist ::= cmdlist ecmd.
 cmdlist ::= ecmd.
 ecmd ::= SEMI.
-ecmd ::= explain cmdx SEMI.
-explain ::= .
+ecmd ::= cmdx SEMI.
 %ifndef SQLITE_OMIT_EXPLAIN
+ecmd ::= explain cmdx.
 explain ::= EXPLAIN.              { pParse->explain = 1; }
 explain ::= EXPLAIN QUERY PLAN.   { pParse->explain = 2; }
 %endif  SQLITE_OMIT_EXPLAIN