Fix using patterns stored as table/set indices

Pattern values used as table/set indices are stored in serialized form
using just the pattern text, but re-creating the value from that didn't
fully initialize/compile the regex matcher after (re-)creating it from
that pattern text.

src/CompHash.cc

@@ -891,6 +891,11 @@ const char* CompositeHash::RecoverOneVal(const HashKey* k, const char* kp0,
 				re = new RE_Matcher(kp1, kp1 + len[0]);
 				kp1 += len[0] + len[1];
 				}
+
+			if ( ! re->Compile() )
+				reporter->InternalError("failed compiling table/set key pattern: %s",
+				                        re->PatternText());
+
 			*pval = make_intrusive<PatternVal>(re);
 			}
 			break;

testing/btest/Baseline/language.patterns-stored-in-containers/out

@@ -0,0 +1,19 @@
+/^?(a)$?/, F
+/^?(b)$?/, F
+/^?(o)$?/, T
+---
+/^?(a)$?/, F
+/^?(b)$?/, F
+/^?(o)$?/, T
+---
+/^?(a)$?/, F
+/^?(b)$?/, F
+/^?(o)$?/, T
+---
+/^?(a)$?/, F
+/^?(b)$?/, F
+/^?(o)$?/, T
+---
+/^?(o)$?/, T
+/^?(b)$?/, F
+/^?(a)$?/, F

testing/btest/language/patterns-stored-in-containers.zeek

@@ -0,0 +1,32 @@
+# @TEST-EXEC: zeek -b %INPUT >out
+# @TEST-EXEC: btest-diff out
+
+local test_string = "foo";
+local myvec: vector of pattern = vector(/a/, /b/, /o/);
+local myset: set[pattern] = {/a/, /b/, /o/};
+local tk: table[pattern] of count = {[/a/] = 0, [/b/] = 1, [/o/] = 2};
+local tv: table[count] of pattern = {[0] = /a/, [1] = /b/, [2] = /o/};
+
+print /a/, /a/ in test_string;
+print /b/, /b/ in test_string;
+print /o/, /o/ in test_string;
+
+print "---";
+
+for ( i in myvec )
+	print myvec[i], myvec[i] in test_string;
+
+print "---";
+
+for ( p in myset )
+	print p, p in test_string;
+
+print "---";
+
+for ( k, v in tk )
+	print k, k in test_string;
+
+print "---";
+
+for ( key, val in tv )
+	print val, val in test_string;