io: in UpdateFromRule properly handle case of std::string and alias without dictionary

[pcanal]

This fixes the issue seen in cms-sw/cmsdist#9643 (comment)
and is the companion PR of root-project/roottest#1256

[github-actions]

Test Results

    18 files      18 suites   4d 9h 13m 37s ⏱️
 2 690 tests  2 688 ✅ 0 💤 2 ❌
46 722 runs  46 720 ✅ 0 💤 2 ❌

For more details on these failures, see this check.

Results for commit a2647e1.

♻️ This comment has been updated with latest results.

[hahnjo]

Please note that roottest-root-io-evolution-make is red on all platforms:

Running test in ./evolution/rules
--- root/io/evolution/rules/execSourceTypes.ref	2025-02-05 07:14:49.266205227 +0000
+++ root/io/evolution/rules/execSourceTypes.clog	2025-02-05 07:39:31.303710009 +0000
@@ -4,10 +4,10 @@
    1.5  2.6  3.7  
 Error in <TStreamerInfo::InsertArtificialElements>: For class Old in StreamerInfo -1 a rule has conflicting type for the source "double fSingle",
    The TStreamerElement has memory type 5 (needed 8) :
-   type=read sourceClass="Old" targetClass="New" version="[1-]" source="double fSingle" target="fDouble" code="{ std::cout << "ERROR: the rule for fDouble should not be run
+   type=read sourceClass="Old" targetClass="New" version="[1-]" source="double fSingle; " target="fDouble" code="{ std::cout << "ERROR: the rule for fDouble should not be run
 "; fDouble = onfile.fSingle * 3; }" 
 Warning in <TStreamerInfo::InsertArtificialElements>: For class Old in StreamerInfo -1 is missing the source data member `fArrayNew` when trying to apply the rule:
-   type=read sourceClass="Old" targetClass="New" version="[1-]" source="A fArrayNew[3]" target="fArrayNew" code="{ examine_array<A,3>(onfile.fArrayNew); for(size_t i = 0; i < 3; ++i) fArrayNew[i].f = onfile.fArrayNew[i].f; }" 
+   type=read sourceClass="Old" targetClass="New" version="[1-]" source="A fArrayNew[3]; " target="fArrayNew" code="{ examine_array<A,3>(onfile.fArrayNew); for(size_t i = 0; i < 3; ++i) fArrayNew[i].f = onfile.fArrayNew[i].f; }" 
 The A value is: 1.2
 The B value is: 5.27183e-315
 The B value is: 1.3
rm execCheckRuleRegistration.clog execSourceTypes.clog execAddRemoveStreamerInfo.log
Tests in ./evolution/rules ......................................... FAIL
gmake[1]: Leaving directory '/github/home/ROOT-CI/roottest/root/io/evolution'

-- END TEST OUTPUT --
-- BEGIN TEST ERROR --
--- Using ROOT from /github/home/ROOT-CI/build
Info in <ACLiC>: unmodified script has already been compiled and loaded
gmake[2]: *** [/github/home/ROOT-CI/roottest//scripts/Rules.mk:759: execSourceTypes.success] Error 1
gmake[1]: *** [/github/home/ROOT-CI/roottest//scripts/Rules.mk:263: rules.test] Error 1
gmake: *** [/github/home/ROOT-CI/roottest//scripts/Rules.mk:299: cleantest] Error 2

-- END TEST ERROR --