Clean up the mess from => patch.

Commit 865f14a2d3 was quite a few bricks
shy of a load: psql, ecpg, and plpgsql were all left out-of-step with
the core lexer.  Of these only the last was likely to be a fatal
problem; but still, a minimal amount of grepping, or even just reading
the comments adjacent to the places that were changed, would have found
the other places that needed to be changed.

src/interfaces/ecpg/preproc/parse.pl

@@ -46,7 +46,8 @@ my %replace_string = (
 	'WITH_LA'         => 'with',
 	'TYPECAST'        => '::',
 	'DOT_DOT'         => '..',
-	'COLON_EQUALS'    => ':=',);
+	'COLON_EQUALS'    => ':=',
+	'EQUALS_GREATER'  => '=>',);
 
 # specific replace_types for specific non-terminals - never include the ':'
 # ECPG-only replace_types are defined in ecpg-replace_types

src/interfaces/ecpg/preproc/pgc.l

@@ -236,6 +236,7 @@ array			({ident_cont}|{whitespace}|[\[\]\+\-\*\%\/\(\)\>\.])*
 typecast		"::"
 dot_dot			\.\.
 colon_equals	":="
+equals_greater	"=>"
 
 /*
  * "self" is the set of chars that should be returned as single-character
@@ -620,6 +621,7 @@ cppline			{space}*#([^i][A-Za-z]*|{if}|{ifdef}|{ifndef}|{import})(.*\\{space})*.
 <SQL>{typecast}		{ return TYPECAST; }
 <SQL>{dot_dot}		{ return DOT_DOT; }
 <SQL>{colon_equals}	{ return COLON_EQUALS; }
+<SQL>{equals_greater} { return EQUALS_GREATER; }
 <SQL>{informix_special}	{
 			  /* are we simulating Informix? */
 				if (INFORMIX_MODE)