[BUILDSCRIPT/5.4] gcc toolchain is not needed

[ghazzor]

5.4 can perfectly compile just fine with LLVM=1 & LLVM_IAS=1, that is the intended way too.

as a matter of fact, 4.19 (might need some upstream), 4.14 (patches for LLVM_IAS) compile just fine with just clang

[ravindu644]

5.4 can perfectly compile just fine with LLVM=1 & LLVM_IAS=1, that is the intended way too.

as a matter of fact, 4.19 (might need some upstream), 4.14 (patches for LLVM_IAS) compile just fine with just clang

yeah, I have to cleanup the build scripts to reduce the jank