g3 and the Angular repo have different versions of TypeScript, and
ts.updateIdentifier() has a different signature in the different versions.
There is no way to write a call to the function that will compile in both
versions simultaneously.
Instead, use ts.getMutableClone() as that has the same effect of cloning
the identifier.
PR Close#23550
This commit adds a new compiler pipeline that isn't dependent on global
analysis, referred to as 'ngtsc'. This new compiler is accessed by
running ngc with "enableIvy" set to "ngtsc". It reuses the same initialization
logic but creates a new implementation of Program which does not perform the
global-level analysis that AngularCompilerProgram does. It will be the
foundation for the production Ivy compiler.
PR Close#23455