[dev.cc] 9a: make RET a synonym for RETURN; use "g" instead of "R30"

Previously, 9a was the only assembler that had a different
name for RET, causing unnecessary friction in simple files
that otherwise assembled on all architectures.  Add RET so
these work on 9a.

This also renames "R30" to "g" to avoid unintentionally
clobbering g in assembly code.  This parallels a change made
to 5a.

LGTM=rsc
R=rsc
CC=golang-codereviews
https://golang.org/cl/178030043

diff --git a/src/cmd/9a/lex.c b/src/cmd/9a/lex.c
index 26f21f7436c35e898fcab66db14dbbe15cdf1d7f..e2945ef89dff4ce9c22f46fd6b57420473b428b1 100644 (file)
--- a/src/cmd/9a/lex.c
+++ b/src/cmd/9a/lex.c
@@ -250,7 +250,7 @@ struct
        "R27",          LREG,   27,
        "R28",          LREG,   28,
        "R29",          LREG,   29,
-       "R30",          LREG,   30,
+       "g",            LREG,   30, // avoid unintentionally clobbering g using R30
        "R31",          LREG,   31,
 
        "F",            LF,     0,
@@ -488,6 +488,7 @@ struct
        "SYSCALL",      LNOP, ASYSCALL,
        "UNDEF",        LNOP, AUNDEF,
 
+       "RET",          LRETRN, ARETURN,
        "RETURN",       LRETRN, ARETURN,
        "RFI",          LRETRN, ARFI,
        "RFCI",         LRETRN, ARFCI,