[cmake] Remove MSVC C4355 override

[RKSimon]

Summary

Remove C4355 : ''this' : used in base member initializer list' from the list of forced disabled warnings.

I'm not seeing any regressions in VS2017/VS2019 llvm/clang builds from removing this.

[rnk]

lgtm

I noticed you can see these warnings by compiling with /Wall, by the way. It's MSVC's equivalent of Clang's -Weverything. So I guess that's the new next level after /W4.

llvm/trunk/cmake/modules/HandleLLVMOptions.cmake

set(msvc_warning_flags
       -wd4146 # Suppress 'unary minus operator applied to unsigned type, result still unsigned'
       -wd4180 # Suppress 'qualifier applied to function type has no meaning; ignored'
       -wd4244 # Suppress ''argument' : conversion from 'type1' to 'type2', possible loss of data'
       -wd4258 # Suppress ''var' : definition from the for loop is ignored; the definition from the enclosing scope is used'
       -wd4267 # Suppress ''var' : conversion from 'size_t' to 'type', possible loss of data'
       -wd4291 # Suppress ''declaration' : no matching operator delete found; memory will not be freed if initialization throws an exception'
       -wd4345 # Suppress 'behavior change: an object of POD type constructed with an initializer of the form () will be default-initialized'
       -wd4351 # Suppress 'new behavior: elements of array 'array' will be default initialized'
-      -wd4355 # Suppress ''this' : used in base member initializer list'
       -wd4456 # Suppress 'declaration of 'var' hides local variable'
       -wd4457 # Suppress 'declaration of 'var' hides function parameter'
       -wd4458 # Suppress 'declaration of 'var' hides class member'
       -wd4459 # Suppress 'declaration of 'var' hides global declaration'
       -wd4503 # Suppress ''identifier' : decorated name length exceeded, name was truncated'
       -wd4624 # Suppress ''derived class' : destructor could not be generated because a base class destructor is inaccessible'
       -wd4722 # Suppress 'function' : destructor never returns, potential memory leak
       -wd4800 # Suppress ''type' : forcing value to bool 'true' or 'false' (performance warning)'