[flang] a few more intrinsics and some style guide comments

Original-commit: flang-compiler/f18@b6696ef923
Reviewed-on: https://github.com/flang-compiler/f18/pull/212
Tree-same-pre-rewrite: false

flang/documentation/C++style.md

@@ -11,6 +11,7 @@ Copyright (c) 2018, NVIDIA CORPORATION.  All rights reserved.
 * Otherwise, where a good public C++ style guide is relevant and clear,
   follow it.  [Google's](https://google.github.io/styleguide/cppguide.html)
   is pretty good and comes with lots of justifications for its rules.
+* Reasonable exceptions to these guidelines can be made.
 ## In particular:
 ### Files
 1. File names should use dashes, not underscores.  C++ sources have the
@@ -163,3 +164,13 @@ build time; don't solve build time problems by writing programs that
 produce source code when macros and templates suffice; don't write macros
 when templates suffice.  Templates are statically typed, checked by the
 compiler, and are (or should be) visible to debuggers.
+### Exceptions to these guidelines
+Reasonable exceptions will be allowed; these guidelines cannot anticipate
+all situations.
+For example, names that come from other sources might be more clear if
+their original spellings are preserved rather than mangled to conform
+needlessly to the conventions here, as Google's C++ style guide does
+in a way that leads to weirdly capitalized abbreviations in names
+like `Http`.
+Consistency is one of many aspects in the pursuit of clarity,
+but not an end in itself.

flang/lib/evaluate/intrinsics.cc

@@ -458,7 +458,8 @@ static const IntrinsicInterface genericIntrinsicFunction[]{
     {"real", {{"a", AnyNumeric, Rank::elementalOrBOZ}, DefaultingKIND},
         KINDReal},
     // pmk WIP continue here with REDUCE
-    // TODO: repeat
+    {"repeat", {{"string", SameChar, Rank::scalar}, {"ncopies", AnyInt}},
+        SameChar, Rank::scalar},
     {"reshape",
         {{"source", SameType, Rank::array}, {"shape", AnyInt, Rank::shape},
             {"pad", SameType, Rank::array, Optionality::optional},
@@ -471,9 +472,13 @@ static const IntrinsicInterface genericIntrinsicFunction[]{
             {"back", AnyLogical, Rank::elemental, Optionality::optional},
             DefaultingKIND},
         KINDInt},
-    // TODO: selected_char/int/real_kind
+    {"selected_char_kind", {{"name", DftChar, Rank::scalar}}, DftInt,
+        Rank::scalar},
+    {"selected_int_kind", {{"r", AnyInt, Rank::scalar}}, DftInt, Rank::scalar},
+    // TODO: selected_real_kind
     {"set_exponent", {{"x", SameReal}, {"i", AnyInt}}, SameReal},
-    // TODO: shape
+    {"shape", {{"source", Anything, Rank::anyOrAssumedRank}, DefaultingKIND},
+        KINDInt, Rank::vector},
     {"shifta", {{"i", SameInt}, {"shift", AnyInt}}, SameInt},
     {"shiftl", {{"i", SameInt}, {"shift", AnyInt}}, SameInt},
     {"shiftr", {{"i", SameInt}, {"shift", AnyInt}}, SameInt},