Fixed #5937 (ValueFlow: wrong analysis of calculations with different variable operands)
Fixed #5959 (ValueFlow: return value from subfunction)
Print callstack in SEH on Windows
Fix cppcheck warning in previous changeset

Signed-off-by: amai2012 <amai@users.sf.net>
astyle formatting

[ci skip]
valueFlowBefore: better analysis of conditional assignment
Fixed #5939 (fp: Possible null pointer dereference, after check against NULL in for loop)
ix compiler warning on Windows 64bit
matchcompiler.py: Show pattern that caused the InternalError
matchcompiler.py: Check Token::type() before comparing Token::str() against "||" or "|"
ValueFlow: Improved analysis after switch
Break the loop once the result can no longer change.
Fixed Token::Match pattern. In x|y|.. patterns, all %cmd% should be placed before plain-text operands.
Fixed wrong configuration of itoa in std.cfg
Several improvements to CheckUnusedVar::checkFunctionVariableUsage_iterateScopes():
- Use AST in some places
- Fixed misusage of Token::isStandardType (fixes false negative)
- Removed some redundant conditions
Fixed 4979 (Doesn't allow any ordering of int modifiers)
Negation not needed anymore.
Fixed and cleaned up Token::Match engine
Reduced Token::Match complexity, better support for complex patterns
Fixed two issues in matchcompiler:
- Use correct findmatch or findsimplematch for verification
- Print failing pattern also for findmatch/findsimplematch