core: build thumb modules with no-tree-vectorize

* Add no-aggressive-loop-optimizations to thumb cflags

Credit: SynergyDev

Change-Id: I2edfe176f338ebbdc36b8e7a1916d103911b13fa
Revert "build/core: Build in ISOC++11 mode if possible"

This reverts commit 833f121c4840a84741d99ecde5663ab78b1a666c.

Revert "build/core: Add option to disable C++11 bits"

This reverts commit a144a7b9b104aaa18d33cdc4de19d21901152003.

Change-Id: I2a62eadc1ecd78847b3297bfdd3f8b86f640fe6b
core/combo: Remove --icf=safe from linker flags

Change-Id: I5faa50924cfb257306ab67d747aade2b2655a2fc