Ben Gamari authored Oct 01, 2019 and Marge Bot committed Nov 04, 2019

Issue #1110 was apparently due to a bug in Vista which prevented GCC
from finding its binaries unless we explicitly added it to PATH.
However, this workaround was incorrectly applied on non-Windows
platforms as well, resulting in ill-formed PATHs (#17266).

Fixes #17266.