Fixes memory leak of ASTContext. A mysterious option DisableFree was turned on, which intentionally leaks the ASTContext for some reason in FrontendAction::EndSourceFile. This patch turns this off and delete Parser instance early so that they will not reference dangling pargma headers.

Fixes memory leak of ASTContext. When DisableFree is turned on, it intentionally leaks the ASTContext as they can be trivially deallocated. This patch turns this off and delete Parser instance early so that they will not reference dangling pargma headers.

Fixes memory leak of ASTContext. A mysterious optioWhen DisableFree wais turned on, whichit intentionally leaks the ASTContext for some reason in FrontendAction::EndSourceFileas they can be trivially deallocated. This patch turns this off and delete Parser instance early so that they will not reference dangling pargma headers.