Document the -cc compile-time option

doc/guide/src/CompileTimeOptions.adoc

@@ -28,6 +28,12 @@ The default varies depending on architecture.
 Pass _option_ to `cc` when compiling assembler code.  If you wish to
 pass an option to the assembler, you must use `cc`’s `-Wa,` syntax.
 
+* ``-cc __cc__``
++
+Specify the executable for the C compiler.  The C compiler is also invoked to
+compile assembly (`.s` files) to object code (`.o` files) and to link object
+code into an executable.
+
 * ``-cc-opt __option__``
 +
 Pass _option_ to `cc` when compiling C code.

man/mlton.1

@@ -49,6 +49,12 @@ Pass \fIoption\fP to \fBgcc\fP when compiling assembler code.  If you
 wish to pass an option to the assembler, you must use \fBgcc\fP's
 \fB\-Wa,\fP syntax.
 
+.TP
+\fB\-cc \fIcc\fP\fR
+Specify the executable for the C compiler.  The C compiler is also invoked to
+compile assembly (\fB.s\fP files) to object code (\fB.o\fP files) and to link
+object code into an executable.
+
 .TP
 \fB\-cc\-opt \fIoption\fP\fR
 Pass \fIoption\fP to \fBgcc\fP when compiling C code.

mlton/main/main.fun

@@ -265,7 +265,7 @@ fun makeOptions {usage} =
        (Expert, "bounce-rssa-usage-cutoff", "<n>",
         "Maximum variable use count to consider",
         Int (fn i => bounceRssaUsageCutoff := (if i < 0 then NONE else SOME i))),
-       (Expert, "cc", " <cc>", "set C compiler",
+       (Normal, "cc", " <cc>", "executable for C compiler",
         SpaceString
         (fn s => cc := String.tokens (s, Char.isSpace))),
        (Normal, "cc-opt", " <opt>", "pass option to C compiler",