main: consider foreign languages when solving the field type specifying _field regex flag

The original code assumed the parser specified in a regex pattern
was the owner of the field specified with the _field regex flag in
the pattern.

For an example, in the option

    --regex-Foo=/.../{_field=afield:\1}...

, ctags assumed "afield" was a specific field of "Foo" parser.
The original code didn't consider an option like

    --regex-Foo=/.../{_language=Bar}{_field=afield:\1}...

In this case, ctags should consider "afield" as a specific
field of "Bar" parser.

NOTE: the language specified with _language flag must be
declared with _foreignLanguage= in --langdef-Foo.

Signed-off-by: Masatake YAMATO <yamato@redhat.com>

Author: masatake

Tmain/list-mline-regex-flags.d/stdout-expected.txt

@@ -10,7 +10,7 @@ p       pcre2                                         use pcre2 regex engine
 -       _advanceTo=N[start|end]                       a group in pattern from where the next scan starts [0end]
 -       _anonymous=PREFIX                             make an anonymous tag with PREFIX
 -       _extra=EXTRA                                  record the tag only when the extra is enabled
--       _field=FIELD:VALUE                            record the matched string(VALUE) to parser own FIELD of the tag
+-       _field=FIELD:VALUE                            record the matched string(VALUE) to the (foreign) language specific FIELD of the tag
 -       _guest=PARSERSPEC,N0[start|end],N1[start|end] run guest parser on the area
 -       _language=LANG                                make a foreign tag for LANG
 -       _role=ROLE                                    set the given ROLE to the roles field

Tmain/list-mtable-regex-flags.d/stdout-expected.txt

@@ -16,7 +16,7 @@ p       pcre2                                         use pcre2 regex engine
 -       _advanceTo=N[start|end]                       a group in pattern from where the next scan starts [0end]
 -       _anonymous=PREFIX                             make an anonymous tag with PREFIX
 -       _extra=EXTRA                                  record the tag only when the extra is enabled
--       _field=FIELD:VALUE                            record the matched string(VALUE) to parser own FIELD of the tag
+-       _field=FIELD:VALUE                            record the matched string(VALUE) to the (foreign) language specific FIELD of the tag
 -       _guest=PARSERSPEC,N0[start|end],N1[start|end] run guest parser on the area
 -       _language=LANG                                make a foreign tag for LANG
 -       _role=ROLE                                    set the given ROLE to the roles field

Tmain/list-regex-flags.d/stdout-expected.txt

@@ -11,7 +11,7 @@ x       exclusive                                     skip testing the other pat
 -       warning="MESSAGE"                             print the given MESSAGE at WARNING level
 -       _anonymous=PREFIX                             make an anonymous tag with PREFIX
 -       _extra=EXTRA                                  record the tag only when the extra is enabled
--       _field=FIELD:VALUE                            record the matched string(VALUE) to parser own FIELD of the tag
+-       _field=FIELD:VALUE                            record the matched string(VALUE) to the (foreign) language specific FIELD of the tag
 -       _guest=PARSERSPEC,N0[start|end],N1[start|end] run guest parser on the area
 -       _language=LANG                                make a foreign tag for LANG
 -       _role=ROLE                                    set the given ROLE to the roles field

Tmain/option-no-such-foreign-field.d/run.sh

@@ -0,0 +1,17 @@
+# Copyright: 2024 Masatake YAMATO
+# License: GPL-2
+
+. ../utils.sh
+
+CTAGS=$1
+
+V=
+# V=valgrind
+
+${V} ${CTAGS} --quiet --options=NONE \
+	 \
+	 --langdef=NOSUCHLANG'{_foreignLanguage=Kconfig}' \
+	 --_fielddef-NOSUCHLANG='NOSUCHFIELD,but this is not the part of Kconfig' \
+     --regex-NOSUCHLANG='/^\# (CONFIG_[^ ]+) is (not set)/\1/c/{_language=Kconfig}{_field=NOSUCHFIELD:\1}{exclusive}' \
+	 \
+	 --_force-quit=0

Tmain/option-no-such-foreign-field.d/stderr-expected.txt

@@ -0,0 +1 @@
+ctags: Warning: no such field "NOSUCHFIELD" in Kconfig

Tmain/parser-own-fields-for-foreign-lang.d/input.unknownx

@@ -0,0 +1,5 @@
+public func foo(n, m);
+protected func bar(n);
+private func baz(n,...);
+X:tagme@iamowner
+Y:iamowner2=tagme2

Tmain/parser-own-fields-for-foreign-lang.d/knownz.ctags

@@ -0,0 +1,4 @@
+--langdef=knownz
+--kinddef-knownz=m,mark,makers
+
+--_fielddef-knownz=owner,the owner of the markers

Tmain/parser-own-fields-for-foreign-lang.d/run.sh

@@ -0,0 +1,15 @@
+# Copyright: 2024 Masatake YAMATO
+# License: GPL-2
+
+. ../utils.sh
+
+CTAGS=$1
+
+V=
+# V=valgrind
+
+${V} ${CTAGS} --options=NONE --options=./knownz.ctags --options=./unknownx.ctags \
+	 --fields=+l \
+	 --fields-unknownx=+'{protection}{signature}' \
+	 --fields-knownz=+'{owner}' \
+	 -o - input.unknownx

Tmain/parser-own-fields-for-foreign-lang.d/stderr-expected.txt

@@ -0,0 +1 @@
+ctags: Notice: No options will be read from files or environment

Tmain/parser-own-fields-for-foreign-lang.d/stdout-expected.txt

@@ -0,0 +1,5 @@
+bar	input.unknownx	/^protected func bar(n);$/;"	f	language:unknownx	protection:protected 	signature:(n)
+baz	input.unknownx	/^private func baz(n,...);$/;"	f	language:unknownx	protection:private 	signature:(n,...)
+foo	input.unknownx	/^public func foo(n, m);$/;"	f	language:unknownx	protection:public 	signature:(n, m)
+tagme	input.unknownx	/^X:tagme@iamowner$/;"	m	language:knownz	owner:iamowner
+tagme2	input.unknownx	/^Y:iamowner2=tagme2$/;"	m	language:knownz	owner:iamowner2