Newly introduced dependency on GCC 7.5.0 should allow any version of GCC 7
The commit 56208a0d introduced a requirement on GCC 7.5.0. I don't think depending on a minor release of GCC makes sense (support for new language standards is added in major releases). The commit's author checked Repology, which is good, but Repology shows the latest version of packages, not necessarily system compilers.
The version of GCC included in NetBSD 9.0 (released February 2020) is 7.4.0, which is good enough to compile the current version of QEMU if the version check is removed. This is a platform for which we're still regularly producing QEMU builds and we'd like to avoid patching out the version test if possible.
Edited by nia