configure --enable-debug --enable-optimize is not enabling optimizations

[pnkfelix]

Running configure --enable-debug --enable-optimize is not enabling optimizations.

Concretely, running ../configure --enable-debug --enable-optimize yields:

CFG_ENABLE_DEBUG     := 1
...
CFG_DISABLE_OPTIMIZE := 1
CFG_DISABLE_OPTIMIZE_CXX := 1
...
CFG_CONFIGURE_ARGS   := --enable-debug --enable-optimize

And, just out of curiosity, I tried switching the order of args; that made little difference:

CFG_ENABLE_DEBUG     := 1
...
CFG_DISABLE_OPTIMIZE := 1
CFG_DISABLE_OPTIMIZE_CXX := 1
...
CFG_CONFIGURE_ARGS   := --enable-optimize --enable-debug

[pnkfelix]

(the fix for this looks easy... i wonder why no one else has been flummoxed by the resulting build times though...)

[richo]

poking at a fix before I crash, mostly because I want to build rust overnight

[petrochenkov]

How much time does it take to build and test stage2 with configure --enable-debug. Days, I guess? I haven't tried yet.

[pnkfelix]

@petrochenkov certainly hours for me, but not a full day

[pnkfelix]

(Note that this bug is only discussing --enable-optimize and --enable-debug, and that is all that is addressed by #24408 ... but there are other flags being overridden by the relevant block of code in configure that probably have a similar problem. I will address that separately (filed as #24416); I want to land #24408 asap.)