The support library contains helpers to parse and emit YAML documents.
In the textual YAML representation, some strings need to be quoted, e.g.
when containing unprintable characters.
We already have such quoting implemented for YAML values.
This patch applies the same quoting to YAML *keys*.
One affected case is output of control registers in AMDGPU Msgpack
metadata, which are printed in a format like this:
```
0x2cca (SPI_SHADER_PGM_RSRC1_ES): 42
```
With this patch, the key is quoted:
```
'0x2cca (SPI_SHADER_PGM_RSRC1_ES)': 42
```
Most test changes come from this pattern.
Summary:
PAL metadata now supports both the old linear reg=val pairs format and
the new MsgPack format.
The MsgPack format uses YAML as its textual representation. On output to
YAML, a mnemonic name is provided for some hardware registers.
Differential Revision: https://reviews.llvm.org/D57028
Change-Id: I2bbaabaaca4b3574f7e03b80fbef7c7a69d06a94
llvm-svn: 356591
