Merge remote-tracking branch 'aosp/upstream'
Mainly for 9dce444 also add a few warnings for unsupported
features.
42ce87c [C++] Do not fail by $(shell) in functions for now
9dce444 [C++] Never specify non-positive -j value
b8517f7 Add implicit_pattern_rule_chain2.mk
28da237 [C++] Explicitly disallow $(shell) in other make constructs
77be80d [C++] Warn about unsupported builtin targets
cbe9f49 [C++] Add a minimal support for .SUFFIXES
3de9ae0 Add delete_on_error.mk
Change-Id: Ia19d8d5f8e5bfb22627aaaa7ed7c461f47b34733
