gmp doesn't build correctly when cross-compiling with clang

The commit in #8497 (closed) added this to libraries/integer-gmp/gmp/ghc.mk:

CLANG = $(findstring clang, $(shell $(CC_STAGE1) --version))

ifeq "$(CLANG)" "clang"
CCX = $(CLANG)
else
CCX = $(CC_STAGE1)
endif

and does the build with $(CCX) rather than $(CC_STAGE1).

However, when cross-compiling, $(CC_STAGE1) could be a clang cross-compiler, but then it's certainly not right to use $(CLANG) = clang, as that is presumably not a cross-compiler.

I don't understand why the issue in #8497 (closed) arose in the first place, so it's unclear to me how to proceed here.

Trac metadata

Trac field	Value
Version	8.1
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Build System
Test case
Differential revisions
BlockedBy
Related
Blocking
CC
Operating system
Architecture